The US had this argument over businesses with "Whites Only" signs and similar, and it was concluded that "just don't go there" is an inadequate response once the problem is large enough.
And if Facebook's policy was "real names for LGBTQFM only", or "real names for gay black Irish jews", I would be right there on the front lines with you in my outrage. Don't mess with the protected classes. But that's not the situation we have here. The situation is, "real names for everyone, regardless of race, color, creed, nationality", yada yada yada. Regardless of how poorly they're implementing it, that's their policy. Don't like it, don't go there.