boring setup. Makes it so that users who want to play 10 player setups with complex mechanics don't feel rewarded when a classic mafia player ends up placing above them in the round. Doesn't promote competitive spirit in terms of advanced play, keeps emphasizing the basics. Tables with classic mafia are bound to be filled with new players who have no idea how competitive mafia works and that NLing and self voting isn't the only thing you're supposed to do as blue, which might further disincentivise players looking for actual competition in mafia. Overall, it may dumb down the competitive userbase.
Sure, it's harder when you don't know who exactly you're looking for. However, some users always tossing games beyond doubt, and it's just funny to see them get away with it because there's someone arguing the 'benefit of doubt'.
In the end, you get to pick 2 of these- 1. Good, competent moderation 2. Clean competition 3. 100% content userbase
I'm pretty sure every abc account I ever banned was an abc account simply because I'd get addmecontacts after each ban. It's pretty much possible to have a 100% success rate over 60-70 accounts