I thought the linearity of Unova was simply too boring. I mean, it was all "after doing X, you can keep going to point Y. Then you need to do Z to proceed."
There was always a glaringly obvious obstacle blocking your path. And the obstacle you first encountered was always the next one to be removed. Totally unlike R/B/Y, where you could go see Snorlax before you took on the third gym, but you would have to finish the fourth one before you could go further. Or yet better, R/S/E, where nothing prevented you from proceeding on from Mauville before even beating the third gym - except a stretch of water that you couldn't cross before you had taken on the fifth. Heck, hadn't Surf required the Balance Badge, you could have gone all the way to Fortree before beating the first gym.
The possibility is slim, but I still hope they fix this up a little in B/W2. Let you roam a little, instead of just clearing one section of the path ahead of you at the time. Let there be crossroads, not just a linear path with dead ends sticking out. Let you have to go back to proceed, sometimes. Pokémon games have always contained the element of "Before you can do B, you must do A", but in BW they took the concept to the extreme and shoved it right in your face.