Is it wrong to discriminate against biological males by denying them access to women’s bathrooms? When I was asked about this today, I pointed to a comment I wrote years ago on the blog: When differences are relevant, it’s not an invalid systemic discrimination. For example, if two guys walk into a bar and the bartender says, “I can’t serve people like you—get out!” Is that wrong? Illegal? One can’t say until one knows why the discrimination is occurring. If the bartender is saying “get out” because the guy isn’t white, then that’s invalid. Why? Because a person’s race is completely irrelevant to the issue of drinking at a bar. But what if he says “get out” because the guy is only fifteen? In that case, the age is relevant because drinking affects youth differently, they don’t have the developmental ability to handle the impairment, etc. Yes, we systemically discriminate against fifteen-year-olds by law because of differences between them and adults, but it’s not invalid to do so.
Source: Discrimination Is Legitimate When the Distinction Is Relevant – Stand to Reason Blog