If I may add my opinion from a different point of view since I am no professional artist and have not posted any work of mine lately. I have avoided Facebook/Instagram/Twitter (the Unholy Trinity!) because it seems to me that 99% of the traffic and interactions in those platforms are just meaningless likes/thumbups/+1's/whatever. You are forced to do it just because there has to be an exchange of "likes" and not doing it may have bad repercussions on your social status!

This might be normal for social exchanges, but when you want to promote your work, likes are not enough. You can post your work there but the monetary rewards are not yours, they are going to the platform owners -- it does not seem right.

Anyway, to keep it short, I totally understand why professional artists migrate to Steemit. Steemit may have the same problems (with spammer, bots, mass upvotes, beggars, etc), but there is one great incentive in addition to the usual benefits of any social network: the monetary rewards.