Seems wishful thinking that New York would owe something to anybody that grew up there. If anything, growing up there should give you the opportunity to have a network already, that would be a local's leg up... from kids you grew up with, to people you practiced music with etc.
This might also be a case of a naive perspective from Billy thinking that the work is all that matters. Nope. Having connections also matters. Do you know bar owners? Do you know venues? Have you done someone a favor that they can pay back? That should be the a "local kid's" advantage. Maybe Billy just didn't form those connections or capitalize on that.
Beyond not feeling bad for taking a side-job, maybe the advice should have been: Network. Get out there, meet people, do favors for people, help them and get help back eventually.