Why? That is just a waste of xp. The RoF quests will give a ton of normal xp if you just go through each zone. If someone stops to grind at all they will wind up being level 100 and all of that Regular XP from quests will be wasted. If all you do is solo/molo then you may be awful at completing all of the quests in the zone, but a 3-box should have zero problems doing them all.
I don't like quests. That being said if you start solely questing in the low 90's you'll still probably end up doing some grinding at some point.
You and I are complete opposites then. I despise grinding. Been there done that long long ago. A quest keeps things fresh and interesting. It gives you a small goal to accomplish as you go about your business of killing mobs throughout the zones. Besides that, you are missing out on the precious Achieves and the ability to request missions.
Ironically I used to work with the guy who basically pioneered the use of achievements style functionality in MMOs. I didn't like them then either. I'll do quests if they grant something I specifically want, like upgraded stats on a charm aug for instance. It's just not my thing. I'm pretty happy with the way RoF turned out in that respect, either playstyle is viable.
I am with Pie here, I really like the totally open sandbox style. If i want to play and advance my character I'd like to be able to go anywhere that is level appropriate and kill stuff. I enjoy the old quests like the epics and old zone keys, but the new stuff with check lists and achievement tie ins doesn't really do it for me. That by no means is saying I don't think that stuff has a place in the game... rather, I'd rather do it the old way.