I think you just contradicted yourself in a way. If Kurt had anything it was talent. That guy came up with some incredible things and having very poor musical preparation. All he did was by ear.
Have you heard David Bowie's version of "The man who sold the world"? Compare the two and you'll see kurt's genius.
He cuold've DEVELOPED that talent but was too lazy todo so. But he had talent, no doubt about that. Just ask Bono