I actually think it would be a good thing if marriage was taken out of the tax code. If everyone was just treated an a person for taxing purposes then there really would be no push for gay marriage. They just want the perks that families get. As someone who has never married, I think it is the right thing to do. For example, I run a household, but because I am the only member of it, I cannot claim head of household. If I had an illegitimate child, why then I could claim it. Makes no sense.
I think you're underestimating the envy, the crazy, and the evil. They can't do real marriage, because they're not willing to do what it takes to "get there." Rather than change themselves, they want to change marriage, minimize it, destroy it.
There is no common ground with crazy people. For them, the self-righteousness, the operatic fuss, and the conflict are the whole point. It's certainly not being married—gay "marriage" divorce rates are through the roof, even for lesbians.