As much as people hated him for it, he did make a few good pointstlozoot said:Ah, the Roger Ebert argument. =p
Player freedom can be a hindrance if you let it, but in a scripted, linear experience the designer makes it so that player freedom is an illusion. Paths you take, objects you approach, scenery you take note of are all planned for by the designer. Good level design means that the player will unconsciously do what the designer wants them to do. Of course players are welcome to abuse the freedom, but then again it's not Shakespeare's fault if you decide to only read the first page of Romeo and Juliet in a funny accent.
Basically I think a well designed game is capable of both allowing the player the illusion of freedom and having them perform and see what you want them to. Whether this has been done skilfully today or not is a matter of debate, but I think it's easy to see the possibilities in the medium.
To some extent I agree with that, although I think it would be hard to draw a line between abusing the freedom and taking extreme liberties with it. Where would you draw the line between reading Romeo and Juliet in a funny accent, or reading Romeo and Juliet in what you think is a perfectly serious dramatic recitation, but in all reality, you sound like an absolute moron? Even with a very linear game like you described, it is possible for someone to feel like really exploring, and end up "seeing something wrong". Something tells me that if gaming does get far enough in exploration its artistic capacities, then this is definitely going to be one our "you just didn't get it" arguments heh. That's why I made that sculpture remark. I think gaming really can learn a lot from sculpture, since they have figured out how to create three dimensional objects with clear points of focus for the last 2000+ years. I'm not sure how much budding game designers study sculpture, but I think there certainly is a rich bank of knowledge that perhaps hasn't been fully tapped.
I think its hard to even speculate on, since as you said, it's tough to know if its been done well or not yet.