>>57843488No they didn't? They made a story choice to explain why the player traversed the lower lands first and notarised them, before beginning to ascend the mountain slopes, unlike in DP where to take advantage of the greater scope allowed by the DS over the GBA, they weaved the region's routes throughout the mountain to make it a natural barrier as the player traverses east to west and back, given the importance placed on HM's, which were used in a similar fashion in L: A and prevented progression depending on how far the player interacted with the plot of the game.
But one game is based around progressing via a formalised battle competition to win competency badges, the other is based around notarising the extant pokémon in a region being settled by outsiders formally and reaching research target levels thus limiting pokémon to a certain area locked until the player plays the game and interacts with the story makes sense, when the progression system isn't keyed to formal battles and handing the kids a pocket nuke won't get them past the balmchucking of the boss battles.