Let's have a school where only people 5'8" and above are allowed. Dwarves are not allowed ...how can you discriminate against a person based on somethign they cannot change?
We do it all the time for very good reasons and sometimes for bad reasons. The US Air Force discriminates against pilot applicants on the basis of height (they have to fit in the cockpit). The army doesn't allow women into combat units on the front lines. Schools require certain mental standards of applicants (you can't change your IQ -- no you can't, not for long). Strip clubs only hire beautiful women as dancers and large intimidating men as bouncers. There are a lot of jobs that require good vision. (Do they have to change the job to accommodate the blind?) Men are not allowed to supervise living quarters of Girl Scout camps.
But answer this question, Cronos: If you wish to make racial discrimination in the private sector a crime, how do you enforce it? Racial quotas? Forbidding IQ tests? How do prove that a person is discriminating by race? I don't think there is any good way to do that in a free society. And I don't want the courts deciding whether or not a person's decision to discriminate is valid or not. I don't want the courts telling us we have to have homosexuals bunking with boy scouts.
The price of freedom is failure. If a businessman discriminates for bad reasons the market will punish him and he will fail.