I just never got into the 'attitude' part of any music scene. I didn't listen to rock music to piss off my parents or as a protest on greater society, or as a release of teen angst. (In fact I rarely paid any attention to the content of rock lyrics, just the melody and syllabic cadence) I just liked the music. And when rock music seemed to become more about attitude than musical substance...well, that turned me off. Punk music I was like, ok, whatever, these guys don't care about sounding good, they prefer to sound offensive. But the new punk and grunge made a slicker form of mainstream 'punk', and ended up crucified by their peers when they made it big. Ha, they became the rockstars they once hated! Ain't karma a bitch
I don't think people who are into punk or grunge listen to it as a way of rebelling against their parents. Maybe some of them do, but most of us genuinely enjoy the music. And they're styles of music that, if you look to their roots, are a lot more diverse than how they've been stereotyped.
But you're right, there was a backlash at the time between the underground scene and the "grunge scene". It was "sellout this" "sellout that". I think Kurt was genuinely trying to take the DIY ethos of punk to a more mainstream audience. I don't know how much Kurt was responsible for the scene not degenerating into a bunch of rock stars in the worst possible way, but after he died, it did become that, and I kind of suspect if he were still alive music would be a lot more diverse and open. Meaning that what it means to be "cool" would not mean limiting yourself to liking one style of music, or dressing in a certain way.
Like him or hate him, Kurt was certainly an alienated person, which does make for a good spirit of individuality. If we had an artist today who was similarly alienated and not just putting on one of these awful pretenses of being alienated that are all too common today, we might all have something to rally around. To be alienated in this world, I think, means to generally be a lover of people, to not judge them for their particular tastes or styles.
Chris Cornell seems like a lost soul to me. I don't think he knows whether to be a rock star or not, but a rock star is the only place he really fits in. I don't think he belongs there, though. I think he belongs in a place like the nineties, or the sixties even, when the music came first and being a cool rock star came second. Pearl Jam stayed true to the cause, they never became self-glorifying rock stars.