People don't need much incentive to do stupid things. There's not much incentive to toss trash out a car window rather than into a bin, but people do that every day.
There's a bunch of mindless minor vandalism that happens on WP because of that.
Some parts of WP are really horrible. Ignore all the obvious places (anything to do with Ireland or Northern Ireland; Israel and Palestine; Abortion; etc). But quiet gnomic uncontroversial edits can get mired up. Someone makes some good faith (and valid) changes to punctuation and spelling. They are quickly reverted by an overzealous twinkle user on "vandal patrol" (wikipedia has done a lot to stop this problem and that needs to be recognised) who also leaves a warning template. The newbie gnomic editor removes the template and reverts the article reversion, and is then receives multiple templates. I don't know how many people have a first experience of WP like that, or find it repeated if they try again, and it would be good to know. But the point of mentioning this is that the toxic parts of WP are a strong incentive to some people to "stick one over" to the WP community. Long term sleeper accounts making a variety of good edits with a few known bad edits; concern trolling; wiki-lawyering; etc. There are plenty of meta-wikipedia places where very long threads can draw in many users to spend a long time talking about stuff which is, at its core, nonsense.
I suspect the future-people may find the meta stuff, especially comparing the meta stuff across different wikipedias, more interesting than actual WP.