I was thinking something similar. If a person has the inclination to jump on the bandwagon for any given situation, they are probably actively getting something out of it.

I have a theory that it could have something to do with the haves and the have nots. Whenever some relatively public figure (by default, without critical thinking, is usually labeled as a "have"), slips up in some way, no matter how small, the have nots jump on the opportunity to join a crusade of righteousness where they strike down the goliath for abusing their unfairly acquired power.