A couple of comments on comments:
* As enjoyable and artistic as Jimi Hendrix was, backhandedly slamming the Monkees seems silly to me. Boyce/Hart and Neil Diamond - not exactly a bad bunch of songwriters, and one could certainly debate the merits of Naismith's later work, but the Monkees were far from a bad band. Perhaps you don't like melodic power pop, or imagine that professional musicians shouldn't form groups by having management types introduce or audition them, but they were very enjoyable for many people.
This of course begets the whole "popular things are often bad" trope.
As for Alice In Chains, Soundgarden, Nirvana and Pearl Jam echoing Metallica .... no. First, those four bands actually have little in common either culturally or musically, other than geography. I once worked for Sub Pop during the heydays of those listed; in their own ways, they all *hated* Metallica and their macho poses. AIC had friends among some of the members of Soundgarden and Nirvana (and Mudhoney, and other bands descended from the U-Men / Green River family tree) but really did not consider themselves part of "the Seattle scene," the Alice Mudgarden thing notwithstanding. Soundgarden were early lumped with Nirvana, but they went heavy and loud as Kurt just got weirder, and most of the members of those bands absolutely despised Pearl Jam, whom they saw as high school jock-types.
For your average Nirvana / Soundgarden fan, there was a lot less distance from Poison to Metallica than from Metallica to their pet band. All that changed right around 1994/after Kurt's death, when Metallica challenged themselves to make different albums, and Soundgarden began sounding more like arena rock with each release.
And let's not forget the utter enmity of Guns n' Roses, by ... well, just about every musician who got a deal after "Nevermind."
I think hair metal began dying when GnR couldn't follow up "Appetite" quickly (or well - sorry, I'm not very taken with Use Your Illusion and the two-CD thing was ridiculous), and then "Nevermind" blew up and it was done. Don't forget that "Gish" was released the same month or thereabouts, and that's one of those things where you could see it coming, but you couldn't have planned it. People's tastes changed, quickly.
Recall it wasn't just a matter of production values and stage wear - there was (at least at first) a very serious attempt to reject what was seen as the regressive ideas of hair metal. (And don't ever slag Ratt, unless you want a cage-match death battle with me.)
Music movements that try to involve politics usually insist on a break with the past, at least until they get watered down. (See: West Coast 60's psych; punk rock v. 1/c. 1977-8; EDM in the 90's). Too bad; I can appreciate the knuckle-drag of "Unskinny Bop" as well as deep cuts on Badmotorfinger, even if that's heretical.