Nirvana rules and Nevermind was a huge deal for alternative music. I don't think linking all those shitty bands to them is very fair because you could do that for literally any past influential band at any point in history. Dave Grohl was a big DC hardcore guy but I'm not gonna blame Minor Threat for Foo Fighters lol.
But on that note, I think Dave Grohl kinda sucks.
I agree with you to some extent. If you draw a long enough line, then we can attribute any band under a “rock” umbrella to Chuck Berry, and that doesn’t do much to explain a lot of what is going on in music. That’s why my Nirvana to Nickelback argument requires a much short line.
In the case of Nirvana, and to be fair we could really be talking about grunge music in general, they made a lot money for record labels in the early 90s. If I’m an A&R guy in the mid 90s, I’m just desperate to catch lightning in the bottle the same way labels did a few years earlier with grunge. So what does that lead me to do? Sign another heavier sounding rock band led by a singer with a groaning vocal, like Nickelback. It doesn’t have to be as good or as influential as Nirvana if it can pay the bills like Nirvana.
As for the Foo Fighters/Minor Threat thing, I agree. You don’t blame Minor Threat for The Foo Fighters just because Dave Grohl came up in the same scene. To me, those bands don’t really have as much in common stylistically. Lemmy was a huge Beatles fan but that’s not something you’d expect from listening to Motörhead.