I understand that argument--and you're not completely wrong--but a) that would require a massive overhaul of our legal system. The whole impetus behind this is that by not being able to be married, LGBT citizens are denied literally thousands of legal rights. That would be a big project. b) Good luck getting our uber-religious society to do so. c) Whether the system is flawed or not, keeping a class of people out of it is certainly not OK.
Oh, I definitely agree that discriminating against a group based on their sexual preference is abhorrent, but I also resent this discussion to some degree because it completely takes away attention from the discussion we should be having and it further legitimizes marriage as something the government should even have involvement in.
For example, if I want to jointly own a home (and only a home with no other possessions jointly shared) with someone, we would not receive a total $500k capital gains exemption on the sale of the home after 5+ years of ownership. Only married people filing taxes jointly get this right. Instead, me and the other person would only be allowed a $250k exemption. How can such a situation possibly be fair? The correct abstraction would have been to allow up to $250k capital gains exemption for each individual on the deed. [0]
At the end of the day, we should be designing laws the way we design software. Strong separation of concerns should be a design goal when drafting legislation.
