The incentive here isn't to pick the side of the fork you agree with; it's to pick the side of the fork you believe will win. So you can't really say that the

The incentive here isn't to pick the side of the fork you agree with; it's to pick the side of the fork you believe will win. So you can't really say that the rollback side winning means that most miners agreed with the rollback - rather it means that most miners thought the rollback side would win. There's a strong element of "self-fulfilling prophesy" here.