I'm pretty sure the entire writing staff changed sometime around when Oblivion came out.
I don't think the individuals own the structure of the quests.
Many of Skyrim's factions have individual hallmarks of a great guild. Companions have an identity, Civil war has Context, Dark Brotherhood has variance and some minor branching, even the Thieves Guild has a persistent feeling to it, and aside from the horrible writing in the main quest itself, has characters that connect around Skyrim.
But Morrowind's factions had all of these hallmarks, except perhaps the Morag Tong. These are really separate issues from what the writing staff's talents would bring to the gameplay department. Not to devalue those. A great quest designer with great writing talent can not only make a fun questline to play, they can also make it paced well, have interesting characters and a meaningful place amidst the rest of the game. Just look at Emil Pagliaro's (I think I spelled that wrong) Dark Brotherhood quests, and pretty much everything in Fallout 3.
I'll also toss my coins into the loop too, in regard to faction duration. Even with the "Unlimited" radiant quests, all of the factions did feel way too short. That's mostly because of the awful pacing. You barely get introduced to Kodlak Whitemane before there's a full-blown invasion on Jorrvaskr. And after what is an
amazing introduction to the College of Winterhold, the faction takes a nosedive to sudden world destruction. It's like Bethesda was afraid that the average CoDpawn's attention span isn't large enough to accommodate plot development. They want their wizz-bangs in the first quest. Screw finding mushrooms, or clearing rats. Screw running Sujamma contracts to thirsty miners, I WANT EXPLOSIONS AND SHOOTEY BOOMS NAO!!!!!!!!!! It comes back to something I said a while ago, that got a lot of anger, but I stand by it. It's not a bad thing to be disliked occasionally, if it's for the right reason. To illicit a strong emotional reaction is the purpose of art, and combining pain-in-the-ass Jobs, with the great, heroic moments that Skyrim saturates the player with creates an important level of contrast that prevents that feeling of "Blah, this again?" from happening at unintended times. (IE: Blah... another dragon?, wouldn't you rather have the player say HELL YES, A DRAGON AFTER THAT IRRITATING SUJAMMA RUN??? BRING IT ON!!!!!!!!!!!)