I agree with some of your characterizations here, but I don’t think it is fair to say that if you are not currently a professional artist, you were never a true artist. People get unlucky, have families to support, etc
Someone who decides, "I'll be a programmer for money," was never an artist. Someone who studies music in college and does admin for some company is not a "musician" and never was. It is the journey in art that makes the artist, not playing a piece.
Unfortunately art is just like that. The amount of time required in devotion to the skill is truly staggering and humbling. And then, it's never enough.
I don't know.
It is possible to make this commitment while working in some unrelated field, but it takes tremendous will-power. Charles Ives is an example I suppose.
You write like the critic from Ratatouille.