The problem isn't that people at RPG Codex hate Morrowind, they hate everything that isn't Fallout 1 or Fallout 2 (in that order). Oh yeah, and Planescape: Torment. All fairly linear games, especially PS:T. Codexers also like KOTOR, which is an extremely linear adventure game without any room for role-playing your character beyond saying "I am good" or "I am evil" and wielding a red lightsaber or blue lightsaber.
Way to generalise, fucker. I don't hear too many kind words said about KOTOR around these parts, and Torment is usually acknowledged for what it is, a story based game that actually uses the strength of a solid narrative to good effect, rather tha being a substandard adventure game with stats, like many story-based RPGs.
You'll also find that Fallout 2 isn't viewed through rose coloured glasses, and many people here are willing to bring its many lesser points into discussion. Nor do we hate anything that's not Fallout, it would be more appropriate to say that Fallout represents an ideal to many of us, and so it is the bar that other RPGs should be trying to jump over, not under.
The arguments that Morrowind is not an RPG are complete Codex ass-wind. Morrowind is the only game where I actually role-played my characters. It's the only RPG that was open enough for you to be able to use your imagination and play your character according to your own ideas.
Bullshit. Nearly every game allows the player to use their imagination and play a character according to their ideas. It doesn't make it a roleplaying game. I can play Doom as a fastiduously clean obsessive compulsive who won't shoot anything at close range to avoid blood splatters, wont venture into radioactive goo without a rad suit, and certainly wont touch blue armour, since it clashes horribly with with his otherwise green outfit.
If the game doesn't account for your imaginative choices, then the RP aspect is inherently flawed. Granted, Morrowind does allow some varied gameplay according to character build, but it's hardly laudable. The choices are no more significant than say, choosing a character class in Hexen. Hell, even the much maligned KOTOR permits as much character variation as Morrowind.
Curiously enough, the "not open enough" game that is Fallout, also permits a great deal of character customisation and development, enabling drastically different gaming experiences. For instance, were you aware that you can complete the entire game without killing anyone/anything? Probably not, judging by:
If you didn't follow the main quest line (were they any others??), you were left to kills mobs pointlessly.
In fact, you're also missing something vital with regards to the "main quest line" which requires only that you destroy the Vats and defeat The Master, and optionally, find a replacement water chip. Everything else serves as optional, but compelling content, that guides the player toward their fuzzily defined final goal. And funnily enough, there's a lot more going on than "killing mobs."
But really, don't take my word for it, go play it again, and explain crop rotation to the farmers in Shady Sands, use explosives to seal the radscorpion caves, covertly break Tandi out of the Khans' base, blackmail Iguana Joe, work your way up the ranks of the Thieves Guild, peacefully resolve the conflict in Adytum, get yourself imprisoned in the military base and successfully escape, etc. In fact, why not go for gold, and talk teh FINAL BOSS!!! into suicide.
There's a whole lot of options in Fallout, if you're willing to use your imagination and role-play as opposed to "following the main quest" or "killing mobs."