I think that him wishing to write off a class of people as of lesser standing is a bit disingenuous. Unfortunately, marriage has become a mix of religious, economic, and legal meanings. In my experience, it isn't so much hating another group so much as feeling like something sacred to them is being coopted and horribly distorted. Having something with the same economic and legal standings but not called marriage generally seems fine by them. That's at least been my experience talking to friends/family/etc. I live in South Carolina for reference.

At the end of the day, we really don't know Eich's personal politics and shouldn't pretend to. Unless he starts on z crusade to "hate the gays" or something equally horrible under the banner of Mozilla, what does it matter?