It seams that between the "1.x was better" and "drop PS3 support NOW!!" arguments we've lost the real point of this thread.

While it's quite true, as many have pointed out, there are invisible wall that serve important purposes. There are also many walls that are quite odd.
You cannot jump on top of Minfilia's desk, why?
You cannot go behind the counters of shops in the market wards, why?
You cannot jump down the stairs to the airship in the Gridania adventurers guild, why?

There are other examples that I can't think of at this time. But there are some invisible walls in this game that they could take out now and it wouldn't hurt anything.