In my opinion it's been steadily more difficult to start constructive topics in the Gambling and Bitcoin Discussion boards. Over the past year, I'd only thought up a noteworthy thread (that wasn't redundant) once, in regards to Bitcoin Discussion. In that sense, it's more of a survivor bias where you are finding solely spam posts because those that care about their posts seldom stoop to that level.
Stop counting posts made in any discussion board to users' postcounts and activities will stop spam-endemic. It is unrealistic to ask for more companies or managers of shit companies/ campaigns to control the post-quality of their participants. This is a very good solution, I think, because the forum and admin still want to give privileges to wear signatures (and get money) for good users.
Spammers will stop spam if their posts won't be counted. When they stop spamming (posts, topics), constructive posts/ topics will appear consequently.
Quite right, and these BMs have no reason to make efforts on stopping shitposting. Cryptotalk campaign campaign is causing huge spam on forum currently, but guess what these spam has what actually made it popular.