Self-voting does often not be intended to cash-out, but to give the own post more visibility in the HOT section. Take a look how much posts are created every hour. It is more than fair, that someone uses his SP to give his own post a little push for more visibility. (Assumed, that his interest is in spreading his ideas.)
- P.S. Same for comments. Self-voting the own comment lets it climb the list of comments to give him more visibility as well. (Just as I did right now.)
Yes, in this sense a useful invention. Those who have the power of the steеm are large, they can always be at the top of the comment line.
Of course I see also a problematic consequence of self-voting to get more visibility. The more SP someone has to self-vote his post, the more visibility gets it and therefor the more votes from other Steemians it can get. In German theres a saying: "Der Teufel scheißt immer auf den größten Haufen." (The devil always shits on the biggest heap.) In other words: Those who have lots of money are getting even more (compared to people with lesser wealth). But that's the way how capitalism works.
Needless to mention. Nothing wrong with self-voting even if it were a cash-out. The issue is when it commands a significant portion of the reward pool to the detriment of the network. To be clear, the issue here is not their motivations behind it, rather focusing on the end result and effects of it.
I'm curious to see the statistics as well, how much of all the rewards are coming from self-voting and how this has changed by HF19. Thanks for this interesting post.