It's not clear to me the behaviour isn't fairly rational. It only seems irrational because the host tells the audience that the faithful are supposed to be find

It's not clear to me the behaviour isn't fairly rational. It only seems irrational because the host tells the audience that the faithful are supposed to be finding traitors -- but they arent. Not at all. They're each aiming to win. Eliminating faithful is a necessary and prudent step. Indeed, traitors have almost all of the power -- the ideal strategy as a faithful is to eliminate talented faithful and ally or sus-out for oneself who the traitors are. In this light, any faithful expressing actual out-loud competence is a target for everyone, esp. other faithful. It seem to me a good strategy is to play dumb, pretend to be confused that a competitor-faithful is a traitor, and target them.