It’s a secular Humanist religious test.
There’s a term someone used on a thread a month or two back, “social” something or other I think, that refers to a position on an issue that most people don’t really care about, but which they use to determine whether a person is an a*****e or not.
People don’t like a*****es, and won’t vote for them.
It’s the same reason why the whole global warming denier label is being used, despite voters never placing it near the top of what issues they care about. It’s basically a shortcut to driving voter behavior without having to focus on substantive issues that work against you.