There are dating sites like you describe — eHarmony, BlackPeopleMeet, JDate, Grindr, etc — and even though they don’t require you to belong to that group, it tu

There are dating sites like you describe — eHarmony, BlackPeopleMeet, JDate, Grindr, etc — and even though they don’t require you to belong to that group, it turns out that most people voluntarily associate that way anyway! Even though there’s nothing mandating it, people just don’t seem to want to sign up for dating sites made for other groups. We’ve also tried allowing these sorts of de jure discriminatory policies. The end result was businesses with signs that said things like “No Negroes” and “Jews Not Allowed”. The solution isn’t to tell people to move to a place where businesses can’t discriminate like that; it’s to make that discrimination illegal everywhere.