That's the rebuttal I thought about too. In particular, the heuristic "if someone is vocal against gays, they are likely to be gay" (whether or not it's true) may arise in practice from the heuristic "if someone is vocal about gays, whether for or against, they are likely to be gay".

I had the impression it arose from the heuristic "If someone makes a verbal status attack a low effort way to handle it is to attempt to reverse it". See also the ingenious reply to "X" that is "Your mom X".