I like what Dave Grohl is saying but my experience with Nirvana was not a good one.In the early 90's I was in a band called Judgment. We were a progressive metal band similar to Queensryche, Dream Theater, and Fates Warning.All those bands at that time were enjoying a lot of success.
My band received major label interest from BMG USA.They had A&R guys come up to Toronto to watch us play, and they were telling us it was just a matter of time before they sign us.It was a very exciting time for us especially since we were from Canada.Some month's past by and they contacted us, telling us they wanted us to write some songs more in the vein of Nirvana, and Pearl Jam. This subsequently led to the break up of the band and the rest is history.Whether it was bands that were getting signed at the time ,or bands that were just playing in bars ,it was Nirvana's music that led to the dumbing down of a lot of music at that time.