Yes, we're all tired of hearing cousin Joe's transparent attempts to rationalize his personal prejudices by convincing himself that 'it's evolution'. And yes, as a general rule, in propositions of the form 'humans exhibit behavior X due to evolutionary explanation Y' the 'explanation Y' part provides very little evidence. But I can't help but notice that this makes a very convenient excuse to dismiss any observation you happen to be uncomfortable with, just because it comes packaged with an evolutionary explanation.

Since the whole topic of human behavior is bound to make people uncomfortable, this doesn't strike me as a winning strategy. Far better to admit that an evolutionary perspective can be a handy tool for identifying fruitful research topics and separating plausible vs. implausible hypothesis, even though the evolutionary explanation does not in and of itself qualify as evidence. Which, of course, is the approach that actual ev-psych researchers (as opposed to cocktail-lounge theorists) generally take.