Spammers are quickly learning that it is not worth it. The downvote/flag hammer of Thor lets folks know this type of noise is unwanted.
As for self-upvoting, this used to be Steem's default position, right? I've got no problem with it, personally. The market will find its balance, and these folks wasting SP on meaningless stuff are just going to shoot themselves in the foot, anyway.
I don't know if they are learning anything. If they are using bots, this is no cost to them. They will run bots even if it only makes them one cent per week!