If that were true, LessWrong would have such an INCREDIBLY HUGE advantage over most every major religion. LessWrong hasn't managed to raise armies and invade sovereign nations yet, after all.

Thinking in those terms, it makes me strongly suspect anyone turned away by a single bad post is engaging in some VERY motivated cognition, and probably would not have stayed long. (A high noise:signal ratio, on the other hand, would be genuinely damaging)