The Max Payne games averaged an 87%, the first getting an 89 and the second getting an 84. These are the only two games from remedy Entertainment I can find.
Quantic Dream made Indigo Prophecy, which averaged an 84%.
I think you are seeing a huge difference between the pedigrees of these developers when there isn't one.
edit: and about your asertion that showing gameplay clips is somehow detrimental to the quality of the end product I call bullshit on that as well. I recall seeing a good number of gameplay clips from LBP, GeoW2, and many other games. Lots of games show gameplay clips from demos, that is a ridiculous reason to think a game won't deliver.
...