Yeah well, you wonder why society has laws.  A small but not insignificant segment of it will try to get away with anything and everything they can, and they make it miserable for everyone else unless they get some consequences thrown in their faces.  If that's how Theymos wants to run his forum, he shouldn't be surprised when the shitposters drive all the constructive ones away, and what he's left with are a bunch of zombie posters all saying the same nonsense in order to advertise shitty ICOs.  Oh, wait.  We're 90% there already.

OP, this idea isn't a new one.  I've suggested it myself in other threads, and there are campaign managers like Yahoo62278 who have already done it.  Theymos doesn't even need to require it.  All it takes is for the managers to want to implement such a thing, and I don't see why they shouldn't.  Seems like a great use of the merit system, though I'm sure we'd be hearing a deafening amount of whining in Meta if shitposters needed a minimum amount in order to get in a campaign.