Well, how can you expect an astronaut to have a good answer to the biggest roadblock? You need to poll some people who tried but failed to become astronauts. They would know more.
Also, I know two astronauts relatively well and they say the same thing when the topic has come up. One took a non traditional approach to being an astronaut, applying many times over years, but still had a hard science advanced degree. It's literally a requirement in the application.
To my chagrin, I will never be an astronaut.
Where there is a will, sometimes there is a way.
So i guess maybe some programs like this will appear in the future...