<<The point is equal rights under the law. Gays want the same privileges that heteros have when in a long term relationship. Civil unions give them that.>>
That's like saying blacks want the same education as whites. Separate but equal could give 'em that. But what you're missing is just the fact that it has to be separate is degrading to them. It means that there are whites who are made uncomfortable by their presence: fair enough, they can deal with that, but the insult is that the law validates the prejudice of those whites against them by giving in to it, by creating a separate school for them.
It is the same principle with the civil union status - - there's no real need for it. But some religious people are uncomfortable that THEY (gays) are availing themselves of something which they (the religious) think belongs only to heteros; and that's fine, the gays can deal with the disapprobation of the religious conservatives. But it's when the law steps in and takes sides, effectively boosting the cause of the religious right, that the insult is made; the gays are "second-classed" into a whole category (civil unions) created just specially for them, only because the religious right were offended (not harmed in any demonstrable way, just offended) by the gays' availing themselves of an institution which every other citizen has a RIGHT to avail himself or herself of.
<<I don't see why the solution is unacceptable. Seems like a win win for both sides. >>
No it's not. It's an official, legal denigration of gays. They know it and so do a lot of other people. There's a right (to marry) and it's not available to them. It's available to any other citizen but not them. And to "console" them for not being allowed that right, a whole new right (which, incidentally, nobody else would ever want) is created specially for them. Given the circumstances in which the new right was created and the continuing unavailability of the original right which sparked the controversy in the first place, it's impossible to see this as anything other than second-class citizenship for gays. It's basically intolerable.