See Civil Rights Act of 1964. Many of the act's opponents were dyed-in-the-wool racists and bigots, and the rest of us can be glad that they lost. But there were some others who opposed the act because they understood that a slippery slope was being created.
Those are the limits most people are familiar with. They're reasonable and expected but even in the US businesses have 'the right to refuse service to anyone.' They work in the same way that you can fire someone, but you can't fire someone for being black, or a woman.
The OP claimed that that did not exist at all in Germany.
