Nothing, except there's no reason for me to do so, improving every bad Wikipedia article I come across would be a full-time job, my edit would probably get reverted by some other overzealous editor who thinks he owns the article, and I can't say that I know very much about most Wikipedia articles I look at (because if I did I wouldn't be looking at them).

That last one might be part of the problem: the only people who edit those kind of Wiki articles are subject experts with some external motivation for doing so.

Improving an article from time to time is a lot more helpful than complaining about it.