What would be the point of trying to pressure a business that is barred by law from doing the thing that you, the consumer, want them to do?
This is why we no longer see mobs of people standing outside schools trying to keep the black kids from going inside.
And why bigots no longer refuse to frequent restaurants that serve people of color. It's not because the bigots no longer exist, but because they know that, even if the owners wanted to, the law forbids all establishments from these sorts of discriminatory practices.
It's clear you want to grant employers almost god-like, controlling rights over the lives of their employees - rather than establishing equal rights between both parties, arbitrated and enforced by law.
Pretty ironic coming from a proponent of marriage equality.
And now, let's test for hypocrisy: Do you support a business's right to refuse services like floral, catering, photography, etc, to homosexuals planning their gay weddings?
It seems to me that where the issue of gay marriage is concerned, you want to have your wedding cake and eat it too.