I think that other people often make the claim that homophobes are secretly gay and I'm asking if we actually know how many, even based on a rough estimate, that applies to. If not, it's a spurious and rather disturbing claim.
This is exactly how stereotypes work. And no, they should not be taking super seriously even if they do tend to come from some real life examples
Personally, I am not super concerned if claims against homophobes are spurious, they do not seem to mind claiming gay people are pedophiles in disguise for example
But as I said, it suggests that queer people are the homophobes. That's my issue. It lessens the bigotry issue if the implication is that cishet people aren't the ones being homophobic.