It's not obnoxious; it's an idiom, or a potential idiom, that wouldn't have caught on if it didn't fill a niche. Your suggested alternatives aren't the same thing at all. A naked quotation doesn't communicate what the quoter is feeling; you can't stick "!" at the end of a quote without changing it; and a free-floating "!" would be still more nonstandard and harder to read than "This."
I think the reason people (including me) hate this particular idiom is that it adds nothing. The quote itself is sufficient emphasis without the sentence fragment "This." attached below it. Oftentimes we see a comment reply consisting solely of the word "This.", again, adding nothing that the voting system doesn't already do a better job of.
And now I have added nothing to the actual topic, which was a somewhat irrelevant to HN but amazing discussion of life in Cairo this week. Sorry.
I'm tired of hearing about the degradation of language content - the 'race to the bottom' of simplified language - being defended as 'just what language does'. Why can't people be proactive about the language they want to use?
What's wrong with someone discussing why they think it's poor, and providing motivation to a 'this'-er to see why it's poor and changing their behaviour towards a more informative approach?
Particularly in an intellectual environment such as what HN wants to fill, why is it wrong to say 'please don't dumb down conversation, please inject content'? After all, screaming 'first post' and trolling are also natural social progressions, but they're frowned on too.
You misunderstand how language changes. New forms always start out as incorrect. Incorrect usages that catch on eventually become correct usages. If everyone stuck to "good" usage, language would stay frozen, which would be a disaster for us humans. Fortunately, we can't control this. Language, as Heidegger said, is the master of man, not the other way around.
Educated people often perceive themselves as defending proper English or whatever against the uncouth hordes. One can see this in the arts, where the same people usually want to perpetuate classical forms. But once a form becomes classical it rarely produces much of lasting worth. Today's classical forms were yesterday's popular (or culturally marginal) forms, while yesterday's classical forms are mostly forgotten today. There are exceptions, of course, but this rule is remarkably stable. It took centuries for Shakespeare to be recognized as classic.
It's fun to note that this rule enables one to make some reasonable guesses. For example, it's more likely that our science fiction, comic books, and movies will be remembered centuries from now than it is that our literary novels will be. (Remember that the novel itself, at the time that the great European novels were being written, was regarded as a guilty pleasure - the way we regard, say, TV. Proper writers wrote drama in verse.) Ditto for rock and roll and hip-hop over orchestral music. And so on.
Once you see that railing against new linguistic forms is just one of those get-off-my-lawn complaints that are forever with us, much as the old always say that the young are ruining civilization, you become free to enjoy how things change. Real intellectual culture is closely connected to the marginal, lowly, and popular; it's pseudo-intellectual culture that wants to erect a wall against them.
Out of curiousity, if we shouldn't correct the language of those we believe are using it poorly, how would one justify the correction of subtle hate speech, which is about stopping language from being used to form a base opinion about a class of people?
Is this not interfering with the way individuals choose to use language, molding language into what we want it to be rather than letting it be what it naturally falls to?
Fair question. It seems to me that language isn't ever intrinsically hateful; what's hateful is the intent with which humans sometimes use it. "Nigger" isn't hateful when Chris Rock uses it; arguably not when Mark Twain put it in Huck Finn either. That's one of the fascinating things about language: the minute you try to pin it down, new usages appear that escape your grasp. Often to comedic effect.
"But once a form becomes classical it rarely produces much of lasting worth."
This may be true of arts, but it's not true of science. A clearly articulated idea does not lose cachet with age. Science isn't about 'forms' and 'styles', it's about accurately describing the world around us. Newtonian mechanics are 'classical' and 'old-fashioned', yet they still provide much of lasting worth to this day.
Anyway, I think to some degree you misunderstand my issue, which is about content. "this" is contentless. It is chaff. Noise. Mental overhead. It adds nothing. I would much prefer to read a rambling paragraph by someone with a poor grammar, spelling, or even knowledge of whitespace if that person is providing some content. Encouraging people to provide content and not just fall back on memes and tropes contributes to intellectual discourse.
All the examples you give provide content of some kind. Encouraging content promotes thinking about content, which in turn gives rise to more sophisticated thought - regardless of crossed t's and dotted i's.
Perhaps an example. I'm Australian, and our previously monocultural British heritage offered us wordplay as a way of life. Every member of society used a variety of forms of metaphor to communicate, and double entendres (not necessarily sexual) were common, as was the process of being able to say more by what you left out. As we rejected the WAP and became multicultural (this is not a jab in that direction, just an explanation), the complexity of this communication has markedly simplified - speaking in metaphor in public is now truly dead here as the great unwashed can no longer perceive the true meaning (which once was plain as the nose on your face). The influx of US media helped simplify things here as well. The art of everyday reading-between-the-lines is wasting away.
So we /have/ lost something tangible here. It's not about 'correct English', but complexity and subtlety in the way we can communicate. Things are much more stark and pinned down now - good for scientific work which should always be utterly unambiguous, but for everyday use not so much fun.
So this has changed. I know that it has to be this way, and it would be unfair to immigrants to force them to engage in communication that takes decades to master just to take part in public life (enough barriers as is). But it is not an 'enjoyable' change.
Perhaps a simile would be: imagine that if to continue communicating you were forced to use words no longer than three syllables long. It's doable, but it's constraining and you lose flexibility of expression.
"Real intellectual culture is closely connected to the marginal, lowly, and popular; it's pseudo-intellectual culture that wants to erect a wall against them."
I couldn't disagree more. I hear the 'erect a wall' part, but the marginal, lowly, and popular are the ones who ridicule those who show intellect or talent. In my experience, the 'good' intellectuals are those who can relate to the common person, but they prefer to be with people who can 'get' them, can converse with them on an equal footing.
And a prime example: "This." is lowly and popular, but real intellectual culture - not hipsters, but real intellectual culture - does not favour it.
This may be true of arts, but it's not true of science.
That would be why I was talking about the arts.
"this" is contentless. It is chaff. Noise. Mental overhead. It adds nothing
It's easy to see that this isn't always true. The "This" in elliotcarlson's original comment - for which he was reamed out and even felt obliged to ream himself out - wasn't contentless at all. Suppose instead he had written: "Here is the portion of the article that I found particularly significant." Nobody would have complained. Yet that would have been 10x as wordy and less idiomatic to boot. I knew what he meant when I read that comment and so, I bet, did nearly everyone else.
(I hope this subthread isn't too contentless. It's certainly offtopic. But language is intrinsically interesting, so I don't feel too bad adding to it.)
It's just language evolution at work.