Because Florida is a god-dammed dumbass.
Not really much else to say, here. Bloody state has some serious g'damn problems and no one major really trying to fix
anything. The social failures are only half the story, really, if that. They're prefaced and supported by fairly horrific economic issues, as well

We're just not doing very well down here, really. I really do want out, but that's still a few years away, realistically. Bleh.
And yeah, Florida pretty much did the same thing re:homosexual marriage, including the let's-shaft-the-unmarried bit, a few years back. From what I remember, though, it was a little different down here in that homosexual marriage was
already unconstitutional -- at least twice over -- and all that really happened was civil unions and cohabitants just got screwed a bit. And by a bit, iirc, I mean something along the lines of the amendment giving businesses grounds to strip parts of insurance support from them, or something like that. S'been long enough I don't quite remember the details, but there was a pretty heavy economic issue (that was, of course, completely drowned out by the anti-homosexual aspect) involved that just kinda' slipped on through and fucked over (or at least gave the room for it) a fairly large number of heterosexual couples.
It was almost hilarious, really, in a really depressing way.