There is certainly no doubt this is a hot topic for conversation! You've got a good point with putting in the algorithm being a statement that self upvoting is acceptable to a point. But is that a bad thing?

I'm thinking out loud here, but are we approaching this from the wrong angle?

What if instead of trying to penalize people for voting for themselves, we make it more rewarding to curate new content? Some sort of additional reward system where you earn an extra percentage for upvoting someone who you have never upvoted before. Of course then some people would just create a bot that randomly upvotes new users without any actual viewing of the content.

So many things to consider!