I wouldn’t put Nirvana along with Pearl JAm and Sound GArden, which were both, obviously main stream.
Nirvana’s first album was definitively obscure and it’s power and directeness was mostly hidden and wrapped in a dark and hazy production by whomever was working in studio for Sub Pop at the time. It’s only the money of David Geffen’s Company and the sound wizardry of Steve Albini that gave them the opportunity to reveal their sound’s qualities on album. At a cost though. To Nirvana’s own appreciation he might have overdone it. If you want to hear what Nirvana themselves wanted for sound, a good enough transposition of how they sounded on stage, you have to listen to the In Utero album.
I saw them live in Belgium and School or Negative Creep are among the most extreme songs I ever heard in rock music. Like some nihilistic machine driving full speed into a wall. Nothing main stream here. The fact that they were so high in the charts just show that the charts can have a good ear on some exceptional occasions.
But you know, I was a teenager in 91 and I can remember one day I met my favorite vinyl shop seller and adviser (this profession doesn’t exist anymore) in a cafe, he had a Nevermind promo copy in one hand and told me : “this will be huge”. So maybe this had to be
There is a huge difference between indie music labels in the nineties and now. In the nineties, the most elitist and obscure little indie labels were still able to help a small band to produce an album. But now, everything has became so corporate in every ways. Some time ago I heard about a funny punk band : Cocaine piss was there name. I thought : "yeah, I have to see that. Went there and saw the most professionnal performance ever. In, every way. It was such a dissonant and disturbing experience on a cognitive level to hear such good punk music, wrapped in such a commercial package. All the codes and syncretisms of punk were there, except one : spontaneity.
On a sidenote, I alkways found english charts had better taste than the US ones. Watch the UK charts compilations by year for the eighties and nineties on youtube and you ll hear some quality music, without doubt.