First off, Wild&TheYoung your answer is here:
I think a more level-headed critical account can be found in Noctir's assessment (which you'll have to scroll down for, but its only 1/4 as long):
Both assessments are damn good, and what makes them interesting is differing opinions on critical points of the album. Noctir thinks Orion has some of the finest riffs on the album, whereas Ultraboris thought the riffs were average and that its coming brought on Opeth and all sorts of idiotic bands trying to make the ugliness of metal beautiful.
I personally think the Ultraboris essay serves more as a companion piece to Some Kind of Monster, in that after seeing Metallica utterly humiliate themselves with that film so many fans were left wondering what the hell happened to their beloved Metallica, and that they simply weren't going to be satisfied with "Cliff died" or "they liked money." Well, if you want that kind of truth, its going to be one truth that you are not going to like and you will swear up and down that its wrong despite the fact that deep down, you know it to be true.
There is one thing both reviews have in common. At the end of the day, Master of Puppets was just a mediocre follow up to Ride The Lightning, and it was really just better off for the world to ignore Metallica and move on to more creative bands/albums the genre was offering, like Pleasure To Kill, Reign In Blood, even Peace Sells. Peace Sells was a better album in my opinion because when Dave brought in the clean guitars, the notes played were not these relaxed interludes, they were buildups filled with tension and suspense. Your ears were fixated because you knew something horrible was coming, and by the time it reared its ugly head, you were already paralyzed with nowhere to go but your inevitable death. Good Mourning/Black Friday as well as My Last Words demonstrate this the best. These two songs chew up Cliff Burton and spit him out.
But here's the problem, music doesn't exist in a vacuum, and in 1986-87, hair metal was on the rise and drastically altering the publics perception of what metal is supposed to be. Because of major label backing, positive press reception or whatever, true metal heads realized that even though Reign In Blood was the superior album, mainstream press wouldn't go within 100 feet of it, and so Master of Puppets was the best weapon they had to combat the glam metal onslaught to popular perception. For whatever reason these idiotic music critics couldn't see that the far superior version of the album was released two years before, choosing meaningless terms like "refined and mature" when they really meant "This is more digestible to me."
The problem was that again, Master of Puppets was a mediocre album, and while fanboys were sreaming "so what if its mediocre, its Metallica!" metal as a whole should have responded "so what?" Rather than shoot for any kind of excellence, such as the death metal directional Pleasure To Kill or Darkness Descends, the "clean guitars are not creative" fuck you mentality of Reign In Blood, the crossover convergence of Game Over and Age of Quarrel, or even a 70s throwback done properly such as Candlemass debut EDM, all you had to do now is play kind of fast at times, throw in a slow section to appear "more than just a thrash band," and well there's your recipe for poison. When you combine that with the commercial and critical success of Metallica's career, you get an album with a reputation that proceeds it and ultimately doesn't live up to the height. I maintain that the success of the Black album helped this albums reputation way more than it ever could have on its own. Especially with the fact that most average people hear of Metallica via Enter Sandman and a common reaction from a diehard is "fuck that shit, they were so much better on their oldstuff" and Master of Puppets would be an album they'd choose because of crosses on the cover or whatever.
If a Ratt or a Dokken released an Orion they'd be ridiculed nonstop for it. But because a hippy who wagged his hair alot and did a thousand note a minute bass solos came up with it, it was ok. Really, even back when I was a Metallica fanboy eating up the likes of Load and Reload I still didn't get what the big deal was about Orion. The guitar solos were cool I guess, but the guitar solo was cool in Walk as well, and that's the lamest fucking riff in heavy metal. Ironically, Slayer, who will never get the Rolling Stone/Spin/Time Magazine respect Metallica gets, were able to fully realize Cliff's ideas -albeit in a much ballsier way- with South of Heaven. An album which, I think is a fast thrash album through and through despite the idiotic masses calling it doom because of two or three slow songs. Lars is as much to blame for not telling Cliff that the reason his ideas were never done before in heavy metal is because Tony Iommi realized those ideas were fucking retarded in 1975 (Fluff was a mistake people, not progress). Lars knew that a jump to a Shout At The Devil type of album (which is exactly what the black album was) would have stopped Metallica dead in their tracks. It would have been a Cold Lake/Turbo like disaster. He had to ease the band into the sellout, and that's exactly what Cliff's hippie tendencies provided. And of course, because Cliff died on the tour of this album, no one will ever have the balls to say that maybe Cliff's concepts weren't such good ideas and that he should have stuck to Joey DeMaio soloing and shut up. Hell, if he was playing Orion during that solo at that fateful Trauma show, would James and Lars have given Cliff a second look?
It's astounding to me how I've been one of the few people to understand this essay all these years. There are folks much smarter than me that have this childish knee-jerk Cliff Burton loyalty and refuse to entertain for a minute any sort of re-evaluation. Isn't that what criticism is supposed to be, folks? Ultraboris didn't call the album the worst thing to happen to heavy metal because it was an audio disaster along the likes of Iwrestledabearonce, he called it that because it was just ok. People, the shit that they are, are much more willing to copy something that is passed off as "acceptable," yet just low-caliber enough so they don't break their backs trying to create something. It's sad how with everything Metallica have done you still have morons that just won't knock Metallica down from the top 3 greatest of all time to 11-15. That's what destroying a legacy is folks. and Master of Puppets was the beginning of that drop. It's just in close enough proximity to the greatness of the first two albums to be considered Number of the Beast when it really should be considered Fear of the Dark.
Do I hate Master of Puppets? No. Hell both reviews hate The Thing That Should Not Be and the non-Mustaine part of Leper Messiah, and I love both! In the case of the latter I think the song is a tasteful tribute to perennial inspiration Am I Evil. I just don't think the album has any business being in the top 20 of any metal list whatsoever. Top 30? Sure.
Strangely enough Don Jameison, however briefly, seemed to understand this too. When That Metal Show was making their top 5 thrash albums of all time list he said the album shouldn't be on there because it's not a thrash album. Smartest thing he ever said. Of course those three couldn't make up their damn minds and Eddie just decided to put the album at #1, cos the segment was dragging on too long. Assholes.