Rottweiler22;
I would think it is because the people who their careers to pursue flying have more motivation to 'make it' in the industry, as they have taken quite a bit of risk to leave everything behind and pursue something which may not eventuate in the end.
Compared to some kid who has his flying paid for and is just interested in the glamour of flying.
As my instructor used to tell me, everyone can fly given enough time to a PPL or even a CPL standard. But beyond that, not everyone has the ability to do it.