Taking rests and using fast travel are both entirely optional features.
Nobody is making you use them.

I would absolutely despise having to walk everywhere all the time, especially on a map as big as the one in this game and this is only EA.
Personally I use the long rests only when I ran out of spellslots, which means that I don't use it very often. However I really see no problem with someone using it as many times as they want, they can play the game on easy mode if they so choose, this is also a totally optional feature, nobody is making you long rest after every single battle.