but they definitely thought it was “worth it.”

How do you conclude that? Is it hard to believe that Paul would write a song, and then realize it wasn't good?

> some artists believe money should never drive why you create a piece of art

Yes, and I'm acquainted with a few of those. They are proud that their art is something nobody else likes. They criticize others for "selling out", meaning making art that others like enough to be willing to pay for it.

They're just trying to justify their lack of talent.

I'm not impressed.

BTW, the Beatles very much enjoyed their money and success.