Um... society's stance on homosexuality has very little to do with religions, but rather the cultural values of its people. Homosexuality has been frowned up since the time of Plato long before the emergent of Abrahamic religions... since it was viewed as "unnatural." Some western societes were more lenient than others.
As it stand, gays are allowed to serve in the U.S. military-- as long it remains a secret. The problem is our society has imposed strict gender roles, even among non-religious folks. So you can understand why others are not really understanding why Obama is focusing on this-- "if you're gay, keep it quiet then you can serve" is probably what they are thinking.
All the loosing of regulations upon gays got nothing to do with morals, but the fact society's values are changing and all that will come out of this is so those that are willing to adopt a gay identity can join.
Frankly, I don't see the problem. If you're in a same-sexed marriage, I can see a problem since it would be part of your legal documents, however if you want to serve-- just keep it shut. The moment you join, you're not white, you're not black, you're not straight, you're not gay-- you are part of the armed forces, representing the branch you signed up under.