Little things make a big difference in your enjoyment. You would not list “cup holders” on your make-or-break features for a car, but you will notice fairly often if they are missing or sub-optimal. If they are really good, you might never notice.
In World of Warcraft, when you mouse-over a monster, the box mentions if you have a quest to kill it. This is very nice if you forget what you are doing with two dozen quests active or are not sure whether you need Prowlers, Young Prowlers, Mature Prowlers, or some or any combination of the three. In World of Warcraft, you carry quest items in your bags. This is not very nice with two dozen quests active or if you need different parts from Prowlers, Young Prowlers, and Mature Prowlers.
In World of Warcraft, you can talk to NPCs from horseback. Mounts are treated as skills, not inventory items. (The Lord of the Rings Online™ will be getting both of these in Siege of Mirkwood™.) You are not dismounted by puddles or nipping wolves.
World of Warcraft has a currency tab. I have read that there are too many currencies with all the various points, badges, and whatnot you can get. Now imagine that problem when the currencies are treated as barter (inventory) options. Would you like to see the variety of tokens in my vaults for The Lord of the Rings Online™?
World of Warcraft treats inventory space as yet another kind of achievement. You buy bags, and bags can be of various sizes. You buy vault slots, then you need to buy the bags for them. Non-tiny bags cost more than you can afford on your own. Unless someone sends you some nice late-game bags, you will spend most of the leveling game with most your inventory full of quest items and basic supplies. The Lord of the Rings Online™ starts everyone with 75 inventory slots, but the only way to increase your space is to buy more vault slots (bag included in the price) or housing. World of Warcraft has no housing. World of Warcraft also has no default button for “open all bags” that I have stumbled upon.
Putting NPCs on platforms, podiums, and stages makes them much easier to click in crowds.