The constitution deals with how the government must interact with citizens. Anti-discrimination laws are, on face, a fundamental violation of freedom of association. They exist by the legal fiction that as businesses serviced by goods that come off federal highways, or are connected to public power grids, all businesses are essentially extensions of the federal government.
As I've said, there's never been a reason to enforce anti-discrimination laws. In fact, anti-discrimination laws have been typically very harmful to minority owned businesses. Harlem New York was a good example of thriving black owned businesses that were gutted by anti-discrimination laws that killed their market share. That's the funny thing about free enterprise: you don't have to use government violence to force people to sell each other stuff. We manged it just fine on our own, even when different people want to go after different market shares.
But hey, you're absolutely right, it is well settled that you can get the courts to help you force businesses that despise you to take your money in certain circumstances. Most of us in the sane camp would just rather do business with people that actually will at least pretend to like us in exchange for our money. But carry on comrade, at least until your on the receiving end of threats of state violence.