That might be the case, but it also might be that honest comments get rewarded. I myself would upvote what I perceive as honest comments. And comments that I think bring something valuable. Being polite and saying things people want to hear doesn't occur to me as valuable.

Also, with SMTs, there will be more ability for communities to reward content that they consider valuable, and people without a lot of stake in that SMT wouldn't be able to downvote and remove those rewards.