Your P->Q is "if PUA works, people will try to denounce PUA". You affirm Q and deduce P.

Ah, okay. Yes to that, although of course I prefer to call it abductive reasoning. I got the impression you were saying something like "kill the status of anyone more successful" was being affirmed.

Now, your astonishingly reductive claim that all social acts are fitness strategies

Never claimed all, but I didn't make it clear enough. The social framework can be used for evolutionary fitness; in this sense, it is an arena for mating struggles. And it is used in this way, and regularly.