Many major articles have their own dedicated team of amateur experts who check the article many times per day. Inaccurate edits are reverted quickly. Wikipedia has a host of system-wide admins who will roll-back poor edits within minutes, and the more blatant vandalisms are usually automatically destroyed by computerized watchdogs. As Levar Burton might say, "Don't take my word for it". Go ahead and try to vandalize a major Wikipedia article. Time how long the edit lasts.
<Tweety Bird>He don't frequent WP much, do he?</Tweety Bird> I mean, sure vandalism is reverted quickly... unless you're a prominent living historian or a living person at all! Or an article is "owned" by a couple of corrupted Slim Virgins keeping the article in a messed up or biased state for one's own agenda. And what about those obscure articles no one cares about and the Vandal Fighters miss?
Did he just encourage us to vandalize? CLOWN REDIRECT!
And isn't "amateur expert" an oxymoron? Or just a regular moron?
OH, THE HILARITY!