But this isn't reviewing a government action; it's reviewing a citizen initiative. It seems like the "community standards" argument must surely hold here if it does anywhere, even if the community is being irrational.
We have a constitution to protect our basic rights from the tyranny of the majority. This is an example of the most important function of our courts.
Yes, it's an citizen initiative, but once passed it is a law that is enforced by the government. When a gay couple goes to get a marriage license, it's the government that is denying them one.