Well devs like Peter Molyneux set high standards for themselves. They want to put stuff in a game, for example, when he said that in Fable 1, if you planted an acorn, and came back to it years later, a tree would be there lol
Sure the xbox had a hardrive so it could have possibly been done, but as development of a game continues, they realise that many of the things they tried to do can't be done.
The latest example is probably Hideo Kojima where he says his orginal vision was not met. But that doesn't affect the game, because they have done the best they can with it.








