It’d get much more acceptance if it weren’t framed in racial terms. The 20th Century taught us not to judge/treat people based on their race. Let’s not forget that lesson.
That lesson isn't something you "learn" just once, and suddenly everything is solved. You have to keep fighting, pressing, insisting that rights are actually applied. If it were true that simply passing a law immediately created equality, the passage of the 14th amendment in 1868 would have solved everything. Women would have had the vote, Blacks a right to compensated employment, Gays a right to marriage, Trans people a right to use the f*cking bathroom. But obviously, that isn't how the world works. You can't tell people it is a crime to identify with a social identifier like race or gender while socially, they are still discriminated against on the basis of those categories. It is painfully obvious that the 20th century did not, in fact, teach us all these admirable lessons.
Don't put people into racial categories and treat/judge them based on that category. Why is that so hard?