You know what I find odd. How many people cannot follow a logical argument, and therefore end up attacking the person rather than the argument. Or perhaps you prefer the Alinsky tactic because you just don't want to talk about the argument. Barber laid out a clear argument and even presented evidence that at least some in the opposition understand the argument and desire this result.
Those argument is not primarily about gays, lesbians, or even same-sex relationships, the argument is primarily defending something we consider good, namely traditional marriage. We consider it good because we see the effects of not having good family all over the place in our society.