I wouldn't say either Morrowind or, especially, Oblivion are canidates for "Best RPG Ever," but the earlier game had a lot going for it. It was definitely a hard game to get into right away. There was very little direction, just a map and a suggestion you go somewhere, but then you're on your own. No real tutorial. Some info boxes pop up when you do a few things for the first time, but pretty much you figure it out as you go along. And I liked this about the game, but it took some getting used to.
The biggest gripe some people have is the class system, which I happen to love. It allows for complete customization, but in a game with no direction, it can leave you creating a pretty flimsy character the first time out. And the manual is no help whatsoever, since it barely talks about custom classes (and the premade ones are only halfway decent, if you're lucky). This is one of those games you almost certainly want a walkthrough for, if only to design a character that won't die on impact.
Morrowind got some of its sense of humor (such as the wizard falling) from the earlier and (in my opinion, of course) superior Baldur's Gate games. But that's fine. It did a good job building on what came before it, and managed to produce something very playable once you realized how the world worked.
Another big complaint from haters is the lack of leveling up on part of the baddies. I don't think this is a bad thing, though I'm probably the only one with this thought. You NEEDED to create a high-level character in order to beat the game, which caused automatic integration of the side quests with the main quests. In Oblivion, the factions were sort of tacked on as though to say, "Well, we had these before, guess we ought to stick 'em in somewhere." In Morrowind it was more a matter of, "Better go join a guild or you'll DIE." I liked that. I liked being able to walk into the same Daedric shrine at level 20 I'd accidentally stumbled into (and had to flee) at level 5. I liked getting that payback. Very satisfying. It felt like I'd actually accomplished something. Whereas in Oblivion, you can beat any quest, including the main story, at virtually any level. What's the point in leveling, then? The main story doesn't even stretch out long enough to build your character's level. You can beat it before hitting level 10. Really?
But the big thing about Morrowind is that once you understand the mechanics, once you have a balanced character, there's really nothing you can't do. I loved that about the game. It embodied some of the best things in a sandbox game, and was flexible enough to cater to power gamers and story fans alike. I'm always big on story and characters, so I was willing to find my way through the dark of the first couple levels before finding the real meat of the game. You have to wade through the murk in Morrowind, but once you do, it's a gem you find. In Oblivion, getting through the opening darkness reveals nothing more than a haze of sameness and stagnation. It deserves the hate it gets, and perhaps its disappointing quality is why some people (myself included) now place Morrowind up on a bit of a pedestal saying, "See, this is what it could have been."