I agree with the last part. Randomly-generated quests can be great for faction quests, such as a mercenary-type organization. It reflects on the fact that the PC is really just a regular member of the faction and would be subject to the same mundane quests as anyone else.
That's not to say handcrafted mundane quests can't be used effectively. Morrowind's guild quests weren't the same scripted "spectacles" like the Companions in Skyrim, but they gradually built up to a larger narrative that is revealed as you progress through the faction.