On the other hand, the players whose decision to boycott the games would have the intended effect of bringing some of the corruption to light and putting pressu

On the other hand, the players whose decision to boycott the games would have the intended effect of bringing some of the corruption to light and putting pressure on FIFA to not do something similar again almost certainly already have enough money to buy Bentleys and attract trophy wives. So, if a star player really feels a certain way about this, I'm not sure the money has as much sway over them as it would over someone else, like you or me, or some lesser known player (whose boycott would have much less effect).