The way how fast travel points are implemented drastically changes the way a person plays and feel during playing so i think by default it should be indeed tuned to gameplay and lore logically (and option can be still given for people like to do it anytime anywhere), personally i like the way morrowind did it: you have this huge world to explore on foot in most cases especialy in the wilderness and there is a default from town to town travel method (that actually gave me a big relief when i was reaching to a town every time) but if you reach certain story points and quests you are rewarded with additional fast travel points (for example being a mage guild member you are able to travel from mage guild to mage guild, at least i think thats not a mod). Also i think certain spells and items eased travelling in the wild which was rewarding
