Most have their own interests closest to heart, I guess. Two-year ranking is an advantage for established and declining players and a disadvantage to new players and up-and-comers. Federer has regularly sided with the last group seemingly against his own interests. One reason, I believe, is comparability. Fed loves the history of the game. Different ranking systems makes for more difficult comparisons between generations. And, of course, he is self-confident enough not to care that much about safeguarding his ranking.
and Fed is old, is more disinterested in the present and has more view on the past of the Tour and also on the future how he will leave it, that's a common state of mind when one has achieved enough and gets near to retirement.
To say the truth, I think that for his own good, he should have left the players' council presidency in the tough present moments (he's been heavily criticized in France for asking too much on the prize money request for instance, as if it was his personal demand, and he's also been criticized by Stakhovsky and others for the opposite reason that he didn't do enough in their eyes), but he didn't resign, which proves that he feels he's entitled/has a duty to do something. That's why old guys are sometimes good in organizations, like Ljubicic, Nieminen as well, Luczak as well in the previous council.