Just copying this post from the Maidenfans forum as it perfectly describes the transition from 80s to 90s Metallica.
Look at it this way — the standard bearers of complex, melodic thrash metal had been finding success on their own terms, playing music that wasn’t really structured for the radio at all, and they had still built up enough of a following to be headlining arena shows. Then they do their first-ever music video and it gets a surprising amount of attention. Good for them.
Now fast forward a couple of years and what happens? The band known for complex song structures, lots of riffs per song, varied tempos, epic harmonized sections, and fairly technical drumming puts out an intentionally radio-friendly album with simplistic song structures, one riff per song, everything pretty close to 120 bpm, wanky solos with too much wah pedal, and simplistic, boring drumming, then churns out the music videos left and right, after saying over and over again back in the day that they’d never do such a thing. They explode on radio and MTV, sell a ridiculous number of albums, and become the darlings of frat houses everywhere. How does that not come off as a sellout?
Then you follow them down the rabbit hole with Load and Reload where they abandon their previous image entirely (logo, physical appearance, etc.), give interviews where they say they’re not a metal band anymore and joke that they should be called “Rockatallica”, put out 160 minutes of music that probably only had about 40-50 minutes of worthwhile material across both albums, and do things like blatantly rehash “Enter Sandman” in the form of “King Nothing”, and do “The Unforgiven II” which rehashes the original song and has Hetfield literally singing “now you’re unforgiven too” in it. Is this ironic performance art? Do they not give a shit? Are they just trolling their casual fans to see what happens? Whatever the interpretation, it sure didn’t look like a creatively inspired band at that point. It looked like they were phoning it in for a payday.
And don’t get me started on St. Anger. That was a bridge too far for most of their fans, including me.
I get that the black album has its fans. It has some really good pop metal songs on it. But if you were already a Metallica fan at that time, it felt like “Metallica For Dummies” — and guess what, a lot of dumb-ass frat boys immediately fell in love with it. Mission accomplished...?