The fear and anger towards anything that isn’t heteronormative almost (but not quite) makes a tiny bit of sense if you remember how these people see things: they think tolerance is a finite resource. Therefore, if you have more tolerance for others, you must have taken some away from them. In their mind, they’re just protecting what’s theirs.

In many of their minds, it’s perfectly reasonable to shoot a thief who has broken into your home. Compared to that, wearing a t-shirt to protect their “property” is easy.