Devil's advocate here:

If a comic is the reason that gay couples should be allowed to marry, and should change our opinions, then how about we all go around getting bit by spiders and hoping we can use web to get around town?

I honestly think we should either be able to marry anyone we want to, or not be allowed to marry at all, but that is just my personal opinion... But I can also understand why older generations don't want this to happen, just look at the time, it's also one of the reasons racism is still strong.