I'm sorry, Bob, but you're wrong. You're so, so wrong.
I mean, I get it. You're this kind of no stops pulled ultra-liberal. I get it. I'm kind of one myself. The problem is that you can't seem to understand that one can be of a conservative mindset without being completely dumb. Amazing, no? But it is the truth.
That wrong underlying assumption nullifies your entire point, since you got the whole thing backwards. You appear to be under the assumption that mankind is on a steady march towards Great Liberal Illumination, with a forgotten bygone Dark Era in which people believed that gays were an abomination that should be sacrificed to Helios the Sun-God and a bright future in which mankind is enlightened enough for Australia to allow an R18+ games rating. That, sadly, is not the case.
See, the thing is... for instance, there's an expression in French that translates vaguely to 'to dress like an Englishwoman', which means something like to be dressed sluttily. That expression came to be because of the Hundred Year War, during which England had far less cultural interchange with Europe, the heart of the world at the time. One of the results is that they didn't follow the changing the cultural sensibilities of the time and when the war ended they were still stick in the cultural outlook of roughly a hundred years prior. Do you imagine what it meant for them? I mean, imagine it had happened during the last century. England would be full of gentleman who would be popping their monocles at our bikin and porn technologies. Surely something like that happened at the time, right?
Nope. During those hundred years, culture had become more conservative. (Or it had in Europe, which in turn made everyone in the world who was or wanted to be civilized act accordingly). So when the war ended and cultural interchange resumed, the English were acting way more liberally than their continental counterparts. For instance, what they accepted to be formal clothing was much more revealing, which gave Englishwomen a reputation of being sleazy. Hence, to dress like an Englishwoman.
Of course, that's just stuff from the old days, and history is boring and full of stupid people who are dead anyway. Right? Except that there are many countries that are more conservative now than they were a hundred years ago. This happens more in the Middle East nowadays; there are many old people who remember the good old days when people didn't have to wear a shirt out at all times and you could go make out with a girl. Would you say those people are nostalgic? Would you say they are stupidly following a dead era that was not as great as they remember anyway?
The truth is that conservatives are not looking at the past through rose-colored glasses. The past was better - for them, because back then being conservative was the more accepted ideology, and policies defending things they still believe in were taken for granted. Conversely, it would have been worse for us - as people had to fight tooth or nail for things we think are right. But the pendulum swings. We're still in the middle of a paradigm shift, but given that social change seems to have been sped up as of late, maybe by the time we're raising our children it will be us who remember the old times when people didn't judge you for being a minority. Nostalgia certainly plays a role, but you're doing it wrong: they don't let nostalgia dictate their policies, they have policies that did much better in the past, which makes nostalgia a strong force for them.
I am not American so I am not affected by your silly dual-party belief systems; my words therefore are true. Hear hear!
It doesn't matter what you are defending, there are smart people and dumb people on your side and on the opposite side. The best way to tell them apart is usually to see if they are capable of understanding people who don't agree with them. If you can't - well, at least the other side has those as well.