Well, you are now getting into the part of the issue of, is "being gay" biological or a lifestyle choice. Where as interracial marriages deal with biological issues (people can't choose what color they are born as), if "being gay" is a lifestyle choice, then the choice comes with consequences. Just as the choice of polygamy doesn't mean multiple partners can be married under the law, the choice of "being gay" would also stand as not being allowed. Now if it ever comes around to be proven that "being gay" is biologic, then it isn't something that a person can change because it is the way they are born. It is at that point where the law would definitely needed to be changed to allow homosexual marriages or the legal practice of marriage be removed from the system all together. But we are not at that point yet. So it isn't bigotry, and it will only be ignorance due to lack of scientific knowledge.
I really dislike the term "lifestyle choice". The context in which it is so often used implies that homosexuality is a
conscious decision, whereas any gay person would beg to differ with such a view. It's about as much of a lifestyle choice as being left-handed. Therefore, why should people have to live with the "consequences" of their supposed decision if they weren't consciously responsible for it, and can't do much to change it anyway?