Note: I will try to avoid directly stating my opinion on Other M. I am merely attempting to explain why people love it, even the obviously bad parts (aka the majority of it.) Please don't get the wrong idea about what I'm saying.
Not to be controversial or anything, but I think I've found why the Metroid fanbase has split along the edge of liking Other M, even if they find it bad. Here's what I propose:
No split yet, barely any franchise.
Everyone loves that one.
Here's where the trouble arises:
What split the fanbase is that Fusion and Prime fixed issues with Super Metroid, but Prime fixed some issues and Fusion fixed others; however, Most Prime fans don't like Fusion as much and most Fusion fans don't like Prime as much.
As Prime was more successful, it developed further that Fusion.
Zero Mission, Echoes
This is where 2D games drop off.
... (no 2D) First Hunt, Pinball and Hunters
Fusion fans were satisfied, but wanted another 2D-style game.
... (no 2D) Prime 3/Trilogy
Prime 3, to me, was a perfect blend of Fusion and Prime. IMO, the apex of Metroid.
But, the trouble arises again. Note, after Prime and Fusion, there were 6 more 3D games and one more 2D game. While this makes sense and all, having more 3D consoles, 2D Metroid and 3D Metroid always felt like completely seperate series to me. Thus begins the crisis of Other M fanboyism.
Most of those who liked Other M were Fusion fans. They liked it because of the linearity, the perception of Samus, and the overall atmosphere. Also, 2D powerups were brought back. Fusion fans didn't care if the game was good or bad; they hadn't seen a Fusion style game in years, and were happy to have another.
Prime fans weren't impressed. They felt Samus was annoying, the linearity was over the top, and that the game was an overall stinker. They felt that the series formula completely changed.
2+ years later, the debate still rages on.
Me? I'm kind of stuck in the middle. I hated Other M's story and cutscenes (including Samus' voice) as well as the unimaginative levels and lack of a catchy Prime style soundtrack. Also, 1st person mode sucked. I did, however, liked the battles, powerups, and Lyle overkilling the Brug. Not to mention MANthony Higgs.
I wouldn't gripe as much about Other M if Nintendo hadn't tried this before. They tried linearity in Fusion, and it was generally disliked. They gave Samus a voice and that too was not well recieved. Sakamoto didn't care. He wanted to satisfy his own dreams. He was angry that Miyamoto and Retro made a (generally opinionated) better game than him. So don't blame Team Ninja; they just handled the cutscenes and aesthetics and what not. And the meteocre soundtrack.
To quote Dr. Anonymous1, " I personally despised the story for several reasons, but I think all of it can be boiled down to one thing: that both Sakamoto and Team Ninja seemed to have made a point of trying to avoid anything remotely resembling SUBTLETY. Think about it: Character Development - In the previous games, we already had gotten a good idea of what Samus' character was like simply by looking at her facial expressions and body language. For example:
1. the grief on her face at the end of Prime as the last vestige of her surrogate family's life burns away. This is very human 2. The rage in her face and the clenched fist that she displays when she sees here nemesis escape the Orpheon. 3. The mixed grief, horror, hatred and pity that is evident in Samus' face when she forces to look away as Gandrayda is absorbed. This is possibly the best example of her humanity, and is also a stark reminder of her own mortality.
All of this and more was beautifully achieved in the Prime series, just by letting Samus' actions and expressions speak for her. I liked that; that was a wonderful idea, and does a wonderfully subtle job of making Samus human, while still keeping that edge to her personality and not forcing it down your throat. That's not to say that SOME dialogue is bad: they did a pretty good job in Fusion! But Other M... My God, where do I begin? Ok, I'll just say it: EVERYTHING SAMUS SAID IN THAT GAME WAS FORCED AND CONTRIVED. Every line she said sounded like Mr. Sakamoto was taking it and shoving it down your throat. There was NO subtlety AT ALL, and thus none of the poignancy that has been of the defining features of the Metroid series. It was just one forced, contrived-as-Norfair line of monologue/unnecessary exposition after another. As a result, Samus herself became forced, and thus made us incapable of sympathising with (or tolerating) her. Real humans are more subtle in our mannerisms than that, and we don't go on long, cringe-inducing rants whenever we draw a breath. It's ironic; they made such an effort to make her "more human" that they pretty much drained the humanity from her! Narrative Foreshadowing and details - In both the 2-D games and the Primes, they dropped subtle hints and bits of wonderful foreshadowing that left you wondering what it could be, and - on a subconscious level - a bit rewarding, after you had spotted them. Examples:
■The silhouette of Nightmare that flew across the background from time to time in Fusion - nothing AT ALL was ever said about this until the time came to fight the creepy bugger. All that time, you were left wondering: "What is that? Why is it following me?" and no answer was given until you were face-to-face.
In Other M, however, barely any "foreshadowing" is dropped without a long, tedious bit of exposition to wave it in front of your face and say "Oooooohhh, look! FORESHADOWING! Didn't spot it? Let's do fifteen close-ups of it!" Essentially, it ruined the whole idea of foreshadowing that has been done so well in previous games. The lesson learned here is, never let just one guy (let alone Sakamoto) write the script for anything. It's just bad news. Character Design: Yes, Sakamoto wasn't in charge of the aestetics behind this game, but apparently he wasn't the only member of "Project M" who has a knack for making a blatant mockery of Metroid. Where Sakamoto thinks that the only way to tell a story is by long-winded, contrived monologues, Team Ninja seems to think that the only one to tell a woman from a man is by giving her oversized body proportions and high heels. I mean, Samus looks like a freaking CARICATURE in Other M! And high heels? That is a heresy that I will NOT stand. And it's not just Samus: EVERY WOMAN in this POS has HIGH FREAKING HEELS! How did that get past Nintendo? And who let Team Ninja do character designing, anyway? I mean, they're not known for using subtlety or modesty in designing their own female characters, so why would Nintendo be stupid enough to let them work on Nintendo's most famous action heroine? Frankly, I'm surprised that Team Ninja didn't push for the inclusion of the "breast jiggling" function that they used in one of their previous games. I guess that's what they call restraint. But again: huge hips, high heels? That's not very subtle. And then there's the enemies: almost all of them are needlessly colourful, and the result looks like one of Dr. Seuss' nightmares. I mean, not only does Ridley look God-awful, but he is bright purple and pink! I mean, ok, he was lavender in the original game, but come on; we've moved on. And where's that cruel, curved beak? Creating creatures and bosses in rainbow colours does not make them stand out; it just makes them look silly. So, all in all, this game lacked one of the key things to why the stories of the Metroid games are generally so good: SUBTLETY. And the story of Metroid: Other M falls flat on its face in this and many other respects. OK, rant over. Any questions? By the way, I may be a Primeist, but I also genuinely liked Fusion, and couldn't really find anything wrong with it."
In conclusion, I think after the series split after Fusion and Prime, the two seperate series developed seperately and had little to do with one another. Other M claimed to bring the two series together and, well, failed to do so. That's why it has such an amount of Fanboys and haters, and causes so much rage.