You are right about self upvoting. Maybe I don't elaborate my thoughts enough. I plan I will write about that in a new post. (will put a link in this comments here).

And by powering down through delegation I don't mean that SP delegated remind on delegated accounts. It just sit there for power down period and then is transferred back to the account from where was delegated.
With this delegates donate something to the community also. On the end this platform make possible earning SP, they chose to withdraw and use it in other ways they want.

I wrote about this subject also in this comment @.