It's not legally debatable in California, because those are the judgments that led up to Prop 8. It's settled law. And it was before Prop 8 aimed to change the constitution to strip equal protection from gay people. Which is why those paying for Prop 8 are literally guilty of trying to break up existing families.
You might believe permanent cohabitation between gay people is different, just like most people who were opposed to interracial marriage. But, in both cases, it's not materially different with respect to civil marriage. Not with regards to equal protection, because no anti-gay bigot has been able to demonstrate in court a rational basis for making that distinction. And not in my experience, where what I see is just like what I see when I visit my straight friends. Happy couples and struggling couples; childless couples and couples with happy, laughing children. Children who deserve society's protection, just like any others.
Regarding the last bit, you can't claim half of society on that. An ever-declining portion of society is anxious, concerned, confused, or misled on gay marriage. I have lots of compassion for them. There are also some people who believe it's against what their god(s) want, but correctly recognized that using the power of the state to impose their religious views on others is wrong. Them, I appreciate.
There are also some bigots -- a much smaller number than the other groups -- who say hateful and false things, as you have. They, and you, can go fuck yourselves. We survived the much greater social upheavals of reducing anti-black bias; we'll certainly make it through accommodating the smaller number of homosexuals. You and your friends can go on to be the Jesse Helmses and the Don Sterlings of your day, muttering into your bran flakes about how it's all going to fall part any day now while your grandchildren politely ignore you and get on with their lives. Enjoy it.