This is a tough one.
While I believe that denying anyone anything based on immutable characteristics is wrong, should someone be forced to sell their private property to someone they don't wish to do business with? If the business is entirely private and not state-owned, why must I open my doors to [insert group of people here]? It would not be government enforced discrimination, but rather the right of a/multiple private individual(s) to decide what can be done with their own property. The individual who has been discriminated against could simply take their business elsewhere. You likely wouldn't see large chains closing their doors to specific groups due to fear of losing profits.