I wonder about people who dont comprimise on their dreams. What happens to those people?

I think I know of a few people who didnt compromise a vision they had when they it. They ended up getting famous and sucessful in spite of the fact that commercial appeal was never a factor in what kind of art they made. Lou Reed and Frank Zappa come to mind.

Whats it like to be someone on a mission like that? I feel like most people who persure an idea like he did could never be famous, let alone support themselves. And yet, he DID get famous. what quality do some people have that makes THEIR pure, unedited expression valuable? Im sure there are a ton of people who create without consiously trying to make their art accessible. Why do some of them get recognised, while others dont? what affects it? and, why?

My big question is what separates a great artist who never considered commercial appeal and a nobody who never considered commercial appeal? does there exist a real, tangible way to measure the value of art, seperate from popularity?