I dont understand your complaint at all. You dont have to fast travel at all. The only areas that are separated are skellige and the main world. I'm not even going to count stuff like the prologue, Vizima, and Kaer Morhen. These are contained quest related areas. Its no different than a loading screen when entering a city in Skyrim.
So the intro orchard is just a small separate piece and a vast part of the game is on one giant map, with some minor exceptions?
If that's the case, I can live with that.