While it's undeniable that the social prestige of a belief is not necessarily dependent on its truth, and that social pressures often prevent people from arriving at true beliefs, it's also important to remember that:

• human epistemic rationality is suboptimal across the board, even in domains where it's not clear how having accurate beliefs would be socially costly;
• even when true beliefs appear to have a social penalty, this need not be the case for a person with sufficient social skill;
• the social costs of particular beliefs vary greatly over time (atheism now vs. in the past; or in the other direction, creationism); and
• people value truth enough to be disturbed when this conflict is pointed out to them.

Hence I would warn against drawing the implication that the aspiring rationalist's project is in any sense futile.