There's a bit of a blogospheric debate going on (see here) about whether conservative nostalgia for the 1950s is, shall we say, a little insensitive. After all the 1950s were a time when, among other things, Jim Crow was in full force, and rapists could go free if the woman was wearing a short skirt. But we don't have to look in too much detail to see what people are really nostalgic for.
The Daily Show's John Oliver figured this out last year (I posted the clip here). When all those commentators and politicians pine for a "simpler time," the time they're pining for was simpler because they were children. Children's lives are usually pretty simple, particularly compared with the life you lead as an adult.
It's true that most of the social changes that have occurred in the last few decades – increasing racial diversity, more equality for women, increased acceptance of gay people – have moved society in a more liberal direction. For some conservatives, particularly older ones, that's all very unsettling. There are other developments, like the decline of unions, that conservatives are happier about. But a lot of this is purely partisan. When your party is out of power, you naturally weave a narrative in which not only is the president a jerk, the entire country's gone to hell. I don't remember much of this "things were so much better when I was a kid!" coming from conservatives when George W. Bush was president and Republicans controlled Congress (someone correct me if I'm wrong).
So when you have that feeling, and you look back to figure out when things were better, it's not too surprising that the time many people settle on is "when I was a kid," whenever that happens to have been. It just so happens that for a lot of people who are in positions of power now, that time was the 1950s.