Why Morrowind, released in 2002, even today attracts so much people and spawn huge projects like Skywind? What's so special for you in this game? Is it alien setting, a feel of mystery, your first rpg or something else?
ps I'm against comparing Morrowind to other games here, or it may lead to holywar, which wasn't the goal. If it still will, just delete the thread.

Perfect combination of
Perfect combination of everything you mentioned plus much more like detailed open world, exceptional graphics (for 2002), believable npcs (even bandits had unique names, in Skyrim you have generic "bandits"), excellent story, unique character development, etc.