The "coersion to participate in gay weddings" is no more and no less offensive to me than "coersion to participate" in any religious ritual. From my POV, they're are the same animal.
Edit:
Aside: The air of superiority in your quote is of the same stripe as the air of superiority expressed by Xians when they claim they'll go to heaven while us sinners will go to hell. The embrace of "gay rights" is evolving into a religion of its own. Believers are superior, opponents and/or agnostics and/or people who don't care one way or the other are luddites soon to die off - which is what needs be done.