I don't upvote myself but I can understand person who have let's say 10 dollars per upvote so he votes on himself to be bigger and bigger like in circle. But I Agree, after HF20 this changes can change situation to force others to upvote others :D - Maybe not this guy you wrote about, but others can change their behaviors.
I don't only understand how some people don't wanna upovote others because they don't wanna to make them bigger and stronger etc. By upvoting other peoples and making some connection you cand find people who upvote you and you them, so everybody get's something to grow together :D
The thing is, steem's design works around curation. By getting rewarded for being selfish, for not using your upvote to curate, for something that goes against steemit's grand design, there should be a penalty.
On HF20 you'll be able to upvote yourself as a means of promotion, but the $ will stay in the reward pool. You'll have to pick between "author + curation rewards and self-upvote weight benefits" and "free promotion" instead of getting both options without penalties.
So if you wanna reward people who upvoted your post you can upvote post to give them more money :D
Yeah, unless they have bad content like plagiarizing etc of course.