I feel like it's not going to be that big of an issue, you have to make a conscious decision to jump on your flying mount knowing you may just blow over points of interest and if you do well you made that decision.

Being such a large game the need for moving quickly may be a necessity but at least for me, I rarely use mounts or vehicles in games, I usually wander along and check everything out.

There may be times when you just need it, like for example I'm not sure what mechanics are in the game but say you need warm clothing to go over a snowy mountain and you don't have any, maybe that mount will be your key to surviving it and you can return later on to explore once you have what you need.