Biologically, the male and female of a species are designed to couple, pass seed and reproduce....THAT IS WHAT THE ULTIMATE REASON IS, FOR PHYSICAL EXISTENCE ON THIS MORTAL COIL.
Same-sex coupling is abnormal-common, yes, normal, no.
To take this to the extreme to make a point:
Some people are attracted to the opposite sex - normal.
Some people are attracted to something else - be it animals, children, inanimate objects (one woman famously married the Berlin wall and got off on rubbing herself against it), the same sex, etc. - not the norm.
Now, before you go on to rant about peadophiles being sick and repulsive, it was not long ago that homosexuals were thought of as the same and, whilst I don't see opinion on peadophiles changing any time soon (and I'm not in favour of it changing) you can surely see that some sexual preferences are away from the norm and, therefore, deemed abnormal.
Afterall, a peadophile could live their life on the right side of the law and commit no abuse against children. Should their views be accepted as normal? Should they be accepted as just people or should we still maintain a "healthy" distrust of them?
As for the armed forces, most of us older members joined in a time where it was preached that to be homosexual was wrong and have lived through most of our careers supporting this view. It will take a little more than a cry for acceptance to change these views.
Personally, I tolerate homosexuals and have been on the receiving end of the attentions of a rather persistant one who also insisted on running around the bar singing "Heeey, I'm a queer" at the top of his voice. I almost got to the point of decking the fecker but decided to introduce him to my wife instead. He finally got the message.