Hmm I'd like to give a definite answer but probably will be just rambling and giving some additional questions :D
Interesting point that whitepaper isn't mentioning proof of brain directly while bluepaper does. Might be, that not the same people have written it?
And I'm actually positively surprised that people still give out more than 50% of the rewards manually. I thought it'll definitely be less. And I'm deefinitely positively surprised how small part of the whole rewards pool is distributed by bitbots. I definitely expected it to be more. The automated services are not a problem in my opinion. As you said, sometimes by joining a group, you become a part of voting trail and then you really don't know whom you're upvoting. The PoB is compromised in this scenario...But if you're autovoting on people you've chosen manually, it kind of goes along with PoB. I kind of think of it as an automated bills. You als don't go to your bank every month to pay them, but you've just willingly set up the transactions for specific accounts. Soo yeah, this post actually is positive for me. Not that many rewards are distributed by bidbots and I'm fine with using autoservices. I don't see any ethical problems there.