Many types of technology are much more advanced. "Send tons of metal and some people hurtling out of the atmosphere without killing them" technology, not as much. In simpler terms, we've had fireworks for centuries. Sometimes you still get a dud. It took multiple tries before the successful attempt; why would we suddenly never fail again after that? It's a difficult thing, and an extremely expensive thing, one people are less willing to pay for without a cold war.
While we don't go to the moon often, we do still go into space, to work on international space stations and whatnot. There's not much reason to keep visiting the dusty moon and plant more flags on it. Technology has not yet advanced enough for us to, say, colonize the moon. When it has, you can bet people will suddenly care about landing on it again.
