We can go down this route and talk about all forms of policy.
Theres no state sales tax on a lot of stuff in MA, does that mean we should abolish state sales tax everywhere else?
We live in a society where we decide how we want to be governed.
Its perfectly rational to want some laws and to not want others.
If the state is going to be involved in marriage, I want people who want to get married to be able to get married...but i want to limit that to only single individuals. No more than two.
Polygamy isn't good for the economy. Gay marriage indirectly kinda benefits economies.
so its not discrimination because its not good for the economy