Somehow, Georgia survived for generations without the state becoming Big Brother.
I think it was a silly, unenforceable law, and it wasn't enforced, except in rare occasions-- when the act was committed in public, for example. I think that law did more harm than good. But the nightmare situation you described as being what would happen, didn't.
I get the sense that you would like to see no laws regarding sexual activity to be on the books, which is fine as an opinion. However, that is about as far out of the mainstream as you were trying to suggest Santorum was in his comments.
As for what I think should be and shouldn't be legal, see post 196.