I dunno, my partner and I have always paid taxes. We've been together for 14 years and haven't had any tax issues.
Child tax credit would suck to miss out on I guess, but we don't have kids so I guess that makes it easier.
There's a reason why gay marriage was such an important battle. Marriage is a legal contract that has numerous benefits including inheritance, right to decide care, visitation rights, and being eligible for benefits to name a few.
It's not just a " piece of paper that says we're in love." It's a huge fucking deal that offers legal protection for your partner and yourself.