I completely get the issue. I, personally, support the right for LGBT individuals to get married. However its not about buying the argument
What I'm worried about is the social ostracizing of those who hold different political beliefs than you. At some point in time it was completely kosher to say the same thing about Blacks. At some point in time, a company that hired black individuals would have had trouble recruiting workers that would have given them a business advantage.
What worries me is that you could say the same exact argument for not hiring Black workers in the mid 1900s - the exact same you posted, and you seem to be completely cool with that. Theres a point where we are now using the same tools of suppression that were used on minorities of past on the now unfashionable opinions of today. I would have liked to think the human race has learned from that experience.