Nevermind changed the music business. That can't be disputed.
The music business changes so often any one band's "relevance" lasts about as long as one of Tritone's self-imposed exiles.
It all depends on whether or not he would have ran Courtney Love through a wood chipper.
I don't know about "relevance," but it might have kept a lot of awful "artists" from quitting their day jobs. It also would have made a mighty fine album cover.