Can you elaborate on the things that cannot properly be displayed in the game?
Well, for instance, reading. Why should a character with little Intelligence be able to read a book which increases their skill? Now, this might seem to "gimp" that character, however the reason his Intelligence is low is because he's already spending more of his time increasing specific skills which have nothing to do with Intelligence.
It's not game changing stuff, but it really reinforces whatever character you play, makes each time you play the game an entirely different experience. Can the game function without it? Of course. But it does increase complexity. Some people might find that complexity frustrating, but frankly there's a lack of complex games and I think Bethesda is the type of company which can push the envelope.
Also, many abilities are really the function of multiple Skills and Attributes. Earlier I mentioned that how well you speak really is determined not only by your Speechcraft Skill, but also your Intelligence and Personality, and in fact the level of your Speechcraft skill should be directly determined by those two Attributes. This also then reinforces logical behavior patterns. If having a good Personality and Intelligence rating allows you to have a good Speechcraft Skill, you are also likely to do other things which rely on Personality and Intelligence.
Now, this is only really important if you could say, play the whole game and not use a single offensive spell or melee weapon. Simply convince your enemies not to attack you, or make good friends with people who can fight for you, or become such a successful merchant that you can hire mercenaries for protection. I doubt these options are in the game, but they are the kind of thing which would push ES from being "Great" to "Astounding."