I agree, but their is a conflict with a gay marriage on a religious level. Many streamings condemn homosexuality; it would be odd for a priest to marry two men or women that are living 'the wrong kind of life' in his opinion. Similarly I find it odd if a couple wants to be married in the tradition of the religions stream of their preference, if that religious branch clearly states that it rejects them.
Of course there's not a broad consensus on the topic of whether homosexuality is an acceptable phenomenon or an abomination - there are many priests out there who're willing to marry a gay couple. But the ratio of 'liberal' and 'conservative' priests isn't exactly 1:1, that should be obvious.
Once again, I absolutely agree with the idea that gay couples should have same the rights as straight couples when it comes to marriage. But a law can't force a change of a religion, that depends on the interpretation of the community that comes with. And even that's a hard thing to change, as they can't alter the basic principles of a religion; if it was that easy they might as well just be Deists.
So Live and let live is my take on this, and that also includes the conservative priests. Let them do what they think is line with their religion and let us concentrate on the next generations of priests, to educate them on this controversial issue.