Jar Jar Binks is arguably considered one of the most annoying cinema characters ever.  Why?  I'm not really sure, I think it's because of the way he talks.  But I'm pretty sure all the people who hate him don't know why either.  Don't get me wrong, I'm not a huge fan, but I don't run around saying "omg, I hate him soooo much, this is the worst movie ever b/c of him!!!!1"  My point is that people love to hate him, just because everyone else hates him.  I once asked a group of my friends why they hated him so much, and they all just kind of stumbled over their words and talked about the "stupid" things he says.  Might I point out C-3PO, who is functions in the same way, yet is beloved by many.  I find him just as, if not more annoying than Jar Jar.

Enough about Star Wars, this is about Vista.  I say Vista is like Jar Jar because it too, is hated by many for no reason.  I have two computers, one running Vista and the other XP, so I can tell you all the reasons you might hate it, and all the reasons it's perfectly capable.  Most people I know, however, just love to hate it.  Example:
Friend: I hate Vista, its so stupid and I don't know why anyone would buy it and windows is really starting to suck.  Maybe I should get a mac..
*later at my place*
Friend: wow, thats so pretty!  Why is your computer so pretty, cake?  Your like, start menu thing is a flag, and it's all colorful and wow!
Me: Um, that's Vista---wait a minute, you just went off on a rant about how much you hate Vista, and you've never even SEEN it?
Friend: Well, my computer-y friend told me it sucked.

The same thing happened when XP replaced Windows 98, so Vista should just eventually fall in place when people buy their new Costco computers with Vista pre-installed and don't want to spend the money to downgrade.

If you have respectable reasons for disliking it, then I'm all for you hating it, but I think a lot of people just hate it for the same reason they hate dear ol' Jar Jar Binks, and that angers me.