Nothing is stopping them. It is a matter of choice.
Dustin Johnson is supposed to be an accomplished athlete in a few sports but has chosen golf. As skilled as he may be, he continues to suffer from a lack of concentration and so he may never reach his full potential.
Wasn't it Bobby Jones who said, "Golf is played mainly on a six inch course; the space between your ears."
“Nothing is stopping them. It is a matter of choice.”
Good thinking.