Yeah, I know what you mean. Kurt’s sense of melody and harmony was pretty advanced. Same with lots of the grunge bands, particularly Soundgarden and Alice in Chains (though the latter is more blues based).
I was bitten by the music snob bug when I was younger. I only wanted to listen to or play stuff that was challenging. It was actually in the early 2000’s when I started teaching guitar for a living that I realized how high quality the songwriting is in a lot music played and written by non-virtuoso musicians is though. The way I taught was to find stuff my students (mostly teens) liked, and I’d figure it out and show them how to play it on guitar. Most of it was stuff they could do on day 1 with no experience. So…really easy stuff. But I was surprised how ‘smart’ the songwriting was in a lot of these tunes. There were some 3 Days Grace songs featuring motivic development that would make Beethoven crack a slight smile.
Rick really focuses on all the small things (pun totally intended) that make songs great. Stellar musicianship isn’t a requirement (though it’s cool when that happens too of course).