He probably also thinks he can come back at any time when he needs a few bucks and he will be fine. This is a lot like the actor who jumps to movies and bombs at it and thinks they can go back to television. It is really hard to go back. Justin will always be able to make a living touring but it is not going to be in 20,000 seat arenas. It is going to be in the 5,000 seat (insert name of Indian casino here) arena for a fraction of the pay.
Being a recording artist means never taking your foot off the gas. Ever. If you are successful you have to keep pressing the gas forever or never be able to get it back.