I am kinda done arguing this, because it is not worth my time to argue with people who don't know what the proletariat even is. But since you seem a bit more charitable, one last attempt before the block:
So please explain how most or all artists are petit bourgeois without pointing out they don't all work directly for capital. If you believe that is how you define it, you are too stupid to actually be on the left. You can see that argument debunked nearby.
Are there a few artists who are petit bourgeois? Sure. There are also a few plumbers who founded plumbing companies and there are cooks who own restaurants. Doesn't make the whole job anything else but proletarian.
As for capital fighting capital: the winner of that fight will be capital. Capital fights itself all the time without our help. I have yet to see you explain how your idea of getting the left involved helps anything.