Yeah, I'm a big fan of the brevity. For me who I follow is about breadth, and the longer people's tweets are, the fewer I can follow. I also think a lot of the >140 tweets I see could easily be written in 140 if the writer worked a little harder. As this edit of Jack's first 280-character tweet conveys well: https://twitter.com/caitlin__kelly/status/912795950476857344...
I see you're not much of a Twitter user, so I can see how you might not be sensitive to the difference. But for me, the 140 character limit has been a great source of writing discipline, getting me to squeeze a point to its essence. If the 280-character version is only arguably better than the 140-character one, then it's circa half as efficient, both in terms of character count and the reader's time. Jack's post was sloppy writing.
And that's really my beef with this change. Twitter is seeking something easy to measure -- engagement of marginal writers -- but willing to sacrifice things that are harder to measure, like reader burden and tweet quality.
Worse, this still won't solve the "need to post more text" problem; you can find a zillion historical examples of people needing more than 280 characters. Thus the unique institution of a tweetstorm, where people had to distill their thinking into a linked set of short, punchy sentences. Thus the less appealing practice of posting an image of text. Thus people being inspired to write longer posts elsewhere and then respond with a well-phrased tweet and a link. I think Twitter would have been far better served to offer text attachments equivalent to image attachments, basically adding a real blogging feature to their existing microblogging platform.
