If you didn't travel that road how would you discover if anything was there? I can't imagine leaving a road untraveled in my games or my life. I must travel them all once or twice and if I enjoy the walk I will travel them again. There could be some witch frozen in the middle of the road that needs my help. I can't go find out if it's not on my map yet.
And if I didn't like fast travel, like I said, I would just not bother to pick that map up or I'd sell it to get rich quick at the start of the game. Discovery can't happen if you don't walk the road unless you are in spoilers or on the wiki looking it up anyway.
Seems it would bring some believability to the map, leave it where you don't have to use it, and encourage the player to explore all areas of the map. I won't walk by a house or cave or dungeon in game without going inside and seeing what is there and I can't find them all unless I walk every roadway.
Perhaps you glazed over my qualifiers. "Maybe, maybe not." You may feel the need to partake in a perfectionism to explore everything, but with games now being around 10 hours long, does Bethesda expect everyone to hold your same span of attention? Maybe, maybe not.
If Bethesda has to make a decision about fast travel, and I suspect this decision has been long made already, they effectively have to pander to one side (for there are two sides, if those poll is at all any indication). It sounds like you, personally, would love it if Bethesda personally put a little into every piece of landscape, but does their fanbase allow them such luxurious real estate? If only 10% of people are willing to explore the map down to the nuances, then spending the man power just to build something does not make sense. If 40% of the fanbase would rather fast travel, there's going to be 40% less content in the wilderness between cities. That's more than just a conjectured amount.
I am part of the dying breed, just like you. I revel in the ability to surprise myself with the little things. "It's the journey, not the destination."
The problem with your statement: "Use it if you want to." is too bifurcating. A game with the map and a game without it are two differently balanced games. To expect both options to be equally acceptable amongst the community is a folly on anyone who believes that can happen. Let's be pragmatic.