'Does that mean a writer can buy they're way to publication by attending writing courses, having critiques and assessments done etc etc.'
I don't believe so. Of course, a 'writer' can improve, but an innate talent is, for me, a prerequisite. Unless you're a celebrity - whatever that means.
Of course, a 'platform' in an interesting or unusual subject helps - e.g. brain surgeon, prisoner of war, circus clown, etc.