The requirements for spaceflight are not so rigorous anymore. There have already been paying passengers (who were non-astronauts) on Russian space vehicles. Much like with a commercial airliner, the pilot has to know what they are doing, and the rest of the people have to know how to sit down and buckle-up. The current issue seems to be that because it is so expensive to send people up, they only send up the very best they can train.