I'm listening to Diane Rehm right now, and there are two military-affiliated guests discussing Don't Ask Don't Tell - one just claimed that abolishing DADT "isn't about gay rights." I can't help but think of the famous I'm not a feminist, but... I believe [explicitly feminist idea] to be true.
Given the very poor job the US military has done of integrating women safely into the service, I find my instinct to roll my eyes at the homophobia driving the policy a little thwarted. If the leadership in the US military doesn't expect itself to be mature enough to deal with potential harassment of gay servicepeople, and we have a ready example of the military dealing poorly with social change, I would be inclined to believe the claim that people would be freaked out by openly-serving gays and lesbians in a way that discipline and official policies couldn't guarantee their safety.
This is not to say that I am comfortable letting the rapists and homophobes dictate who can and cannot serve to defend this country. Though, knowing the stats about sexual assault in the military, I would definitely discourage my daughter from entering. It would sure be nice if Americans could grow up already and realize that women and homosexuals (do I need a Venn diagram here?) are currently and have always been contributing to every sector of society.