- You can't add or edit anything without someone picking a fight.
- Everyone with an account there that's been there longer than a month feels as though they're better than everyone else - and thus give out unbacked warnings to people they don't like like there's no tomorrow.
- You can't create an article without it being deleted you a pile of people giving you unbacked bogus warnings (see above)
- When writing, making the slightest of implications that something fictional is real gets you banned.
- Unless you're writing in a sci-fi or fiction article, in which case making the slightest implication that the fiction you're writing about isn't real gets you banned.
- World viewpoints are ignored in favour of american viewpoints, disregarding the validity (or lack of).
- America is over-emphasised like mad. (take, for instance, swine flu. When swine flu had taken around 600-700 lives in mexico, the wikipedia listed every single remote suspected case in america, organised by state in alphabetical order (this was before swine flu broke out there), but mexico's hundreds of deaths received nothing more than a "There have been over 600 deaths reported in mexico."
- People try to find any possible reason they can to revert your edits, even if you're just correcting spelling.
- People look through your contributions and try to find a reason to revert all of them.
- The creation of certain articles are banned because of "lack of notability", disregarding the fact that the point of the wikipedia is that it doesn't have the restrictions that physical encyclopædias have.
- They refuse to allow linking to other wikis - which, when combined with the above, leaves a massive irreparable hole in the knowledge accessible from wikipedia.
- You bloody get banned for expanding on articles that are deemed not notable enough. I mean, what the fuck?
- The people that have been put in charge of it by it's founders are ignorant, arrogant, obtuse, and -oddly enough- inconsistently stubborn.

Yes, I just felt like a bit of a rant <.<