Anyone that tried to set up a new email domain will tell you its quite a serious task. Email spammers are constantly on the run, setting up new domains, changing up the content to evade spam filters. Its very time consuming, hard and unpredictable. It time for social media to close the gap with email and make spamming effectively as hard.
I postulate that if we applied similar techniques to social media after a couple of years online discourse is going to improve. Or we are not going to do this and the death of the open internet will continue.