I never said you did, L. But that is a sentiment I see often on the topic of jump.
The funny thing about that is that having to walk around everything from low fences to pebbles on the road is more immersion-killing than having the ability to jump would.The fact that a lot of people have played the game for months and never thought "Gee you know what this needs? Jump!" is case enough.
Secondly, character movement, despite what some may thing, is not smoothed out. Adding jump requires them to smooth character animations and reactions between player input (controller or keyboard) and the character moving. This is big to me because I want to see boss encounters that involve more movement and positioning and I know I'm not going to see that based on what we have right now.
Thirdly, dungeon design suffers a bit because you can't have ledges, platforms or anything of that sort. It all has to be ramps in order to move about. Concerned about players getting to places they shouldn't? Invisible walls are the answer there, probably associated with walls of smoke or columns of fire, or in the case of the Garleans, could even be lasers and force fields to keep things in theme.