I almost agree with machaca.
You must remember, first of all, that whenever the government 'recognizes' something, it regulates it and usually encourages it, one way or another, at my expense. I simply don't want money stolen from me and thrown at gays - and yes, if money must be stolen from me and thrown at someone, gays are pretty close to the bottom of the list of people I'd like it thrown at. 'Why' is irrelevant: if, as you say, their deviated preversions are none of my business, well, neither is it any of your business if I think they're a bunch of deviated preverts.
Second, as a matter of practical politics, if you want the government out of the marriage business, it's stupid and self-defeating to demand that they get more into it. Do you really believe that it's bad for government to regulate marriage? Do you really believe that markets and societies work? Well, here you have a test case. Make it work. If government interference keeps it from working, for God's sakes, if you really believe what you say you do, get the government to interfere less, not more - and if you can't swing that, then at least do your best to make sure everyone understands who's at fault. Frankly, the last thing any of us need are a bunch of fair-weather libertarians who, at the first sign of trouble, go squealing to their masters begging for their oh-so-benevolent rule under such dishonest banners as 'equal protection'. Do that, and you might as well be a Republican.