It's not unwatchable.
(It does some of the really ignorant "Hey Christians, if you hate gays why don't you follow the entire canon of Jewish law" business, which bugs me. An informed Christian-bashing is a more effective Christian-bashing.)
Could you explain the distinction? I'd like to understand, and I don't see it. To my mind, the Bible says a lot of things that seem completely crazy. Its interdictions against homosexuality fall into that category. I'm not sure how that is simple-minded, and I'd like to understand.
People who actually have to deal with homophobia and anti-gay forces in our world, frankly, need to marshal every available argument. It's not an easy task.
Also, fighting back against anti-gay Christians is not the same thing as Christian-bashing, although anti-gay Christians would probably like you to think so. For example, I am both gay and Christian, and I don't interpret most criticisms of Christianity with respect to gay/lesbian issues, or practically in any other context, as an attack on my faith. I sense that you already kind of realize this, and I don't mean to be obnoxious about it.
Gay and lesbian people are feeling a little demoralized right about now and could use some help from our straight allies.