Because that's how people know that you know what you're talking about. I've seen many factually incorrect, heavily upvoted posts here on HN, and credibility is part of what lets me identify good material. For example, there was a post in the last few weeks about DNS -- I knew that davidu's answer was the one to trust, even though others were more upvoted.
Speaking as a scientist, "don't think about it, don't care about it, just trust someone" is contrary to my nature.
I was born with a burning desire to understand. Everything. I just wish I could locate a group of like-minded people to work with. I've been somewhat dismayed to find that "the real world" consists mostly of people whose sole ambition (or sole reality) is to fulfill their current role, without ever analyzing what it is they are doing or striving to improve the overall project.
Status is very important. I wish it weren't so. At my last job, I was using EC2 to devise solutions to problems that they truly believed were technically unsolvable --- but no one would listen to me, because I was a newcomer. Their faith in the senior technical engineer was absolute and unwavering, and the senior technical engineer believed it was unsolvable, so therefore it was, for all intents and purposes, unsolvable. (After all, nothing ever came of my research, because no one cared enough to listen, or had time to think about something other than their current, immediate goal.)
Worse, they even became offended when I tried to research the "unsolvable" problem in my own spare time. Status really sucks.
I feel the same way about understanding things, but I don't have the time to understand every concept in the world from first principles. Nobody does.
When there's a discussion on DNS, I like to know what's going on, but I can't take 2 years to go learn everything there is to know DNS (Well, I could, but I'm not going to). Luckily I know there is someone here who has done this, and until I have more or better information, I'm going to trust him. It's a necessary shortcut.
Status often does suck, but it's a necessary evil. There is too much information out there -- filters of some kind are necessary, and status is more reliable than most
