I guess at what point does it become disheartening for people with high musicianship skills to see that people who may not have the chops are finding mega-success? Or maybe it's less of a disheartening fact and more of an inspiring one for those who may not be guitar heroes? Idk I guess I admire Cobain's/Dylan's ability to just write catchy stuff (even if it's laughably simple to players) and not care that their plateaued in their playing ability. Perhaps they just downplay their abilities as well...
Never mistake art for commerce. They are not always mutually exclusive - but mostly are. Great musicianship often has nothing to do with success or notoriety. Take Satriani, Holdsworth, Malmsteen, etc. NONE of them are even remotely successful compared to your average pop band - or for that matter guitarists that hit the mainstream - Van Halen, Stevie Ray Vaughn, John Mayer, etc.
The main difference in guys like Van Halen - (and I would respectfully add Syn to this list) is platform. If you have great songs and a successful band - you are naturally going to be a lot more well known than a guitarist with OK songs and no band.
Great songs (and their associated bands) live forever. Great guitar players (without hit records) have much more of a cult following.
Last point. If your band has great songs and you become a guitar legend (like Van Halen), then you can live off of that "guitar slinger" success as well as your songs.
Bottom line: 99.9% of the general public will ALWAYS prefer a Cobain over a Satriani. And 99.9% of guitar players will always prefer Satriani.
Is it disheartening? Sometimes.