I think they saved RnR from the sad parody it was becoming with hair metal. However, I don't know how folks can throw Nirvana and PJ in the same category. They both got the "grunge" label but that's only because the dilettantes thought two things; 1. They weren't hair metal and, 2. They were both from Seattle. I can see how some folks might find Nirvana to be a little grating. They had the DIY punk thing going (although their big albums were with Albini and Vig at the helm). However, and I'm not really a PJ fan, Pearl Jam was far from a 3 chord punk band. PJ's songwriting is a throwback. Yellow Ledbetter is a Little Wing ripoff, I think McCready has said as much. Nirvana was about attitude, honesty, and melody. PJ were song craftsmen.