Very few people do, which actually makes it worse: of course the spammers and the hustlers are still motivated, so the needle moves more firmly into the territory of "most newcomer contributions are made in bad faith". Editors and admins feel increasingly under siege, so they respond more aggressively to everything.

It's basically the same problem as with real-world policing: because the cops overwhelmingly have deal with "problem" cases (you call them about burglars or drug dealers, not to tell them you baked some cookies), they develop a skewed perception of the average citizen and... well.