The merit requirement does prohibit most shitposters from ranking up, but it doesn't prevent them from participating in bounties. We've had this discussion before, and it's off-topic here, but I think if those bounties would require a minimum rank OR a minimum amount of earned merits, that'd be the final nail in the shitposting coffin.
According to hilariousetc on another topic, giving a merit requirement for joining bounties will only make them want to buy merits from other sources.
In my opinion, this can be both good and bad.
Good because we can identify the unscrupulous merit source and theymos can remove their privileges accordingly.
Bad because some people who made good posts but not yet received enough merit would have to wait - so I guess its a job better left to the hands of the bounty manager
When both solutions are bad, one has to choose the better solution even if its far from being perfect. Yes, making a merit/rank requirement for bounty participation will create a whole new black market of merit trading (if it doesnt already exist...). It will probably have other unwanted effects. However, it will reduce the spam. Dramatically. I believe spam is currently
the largest and most annoying problem in BTT. Solving it should be top priority even if new issues would arise.