Yes it is wrong to make ppl to go against their religious beliefs. It is more wrong for them to discriminate against the public. One outweighs the other in the big scheme of things. So too bad so sad. The world is bad enough without endorsing hate. Marry the gays or close the doors to the public.
What's wrong with freedom of association? The government should have no say in who a person does or does not associate with, including who they do business with.
If the owners want to forgo the revenue of a gay "marriage" then power to them.