NB - if you ever need a perfect example of cynicism this post is it - in which @therealwolf basically condemns the current incentives system, but at the same time he runs a voting bot which profits from this system.
Amen!
The topic of trust in Proof of Brain was explored in an old blog post of mine, whose link is included for your reading pleasure.
https://steemit.com/steem-network/@novacadian/where-is-the-trust-in-proof-of-brain-mining