Sure, make sure I've explored a place before I can FT to it. I can deal with that. But beyond that, I don't see why Fast-Travel needs to be packaged with some form of innate and arbitrary "cost." I don't see how that brings anything to the table.
To change it into a system like RDR och GTA would probably be good however.
Personally, I find that to be a myth. I'd consider myself a "hard-core" player. Insofar as if anyone is one - then surely I'm one of them. (Though to be honest, the whole "hard-core vs casual" thing I find to be a rather onerous example of society appropriating a term thought up by marketing research groups to figure out how to make social networking sites more profitable.) But I digress...
My point is that I don't consider myself to be "casual" in approaching a Bethesda game (or any form of RPG, or even most videogames in general.) But I like having the freedom to fast-travel. The concept that I can "fast-forward," by an intimated time compression, from one place to another - but only by use of a Silt Strider or some other vehicle (when I'd be able to walk there just as easily,) is something I find "immersion-breaking." That it takes place via an arbitrary form of transportation doesn't, to me, make that loading screen any more immersive. Putting arbitrary restrictions isn't something that, IMHO, I would consider to be a compromise that would please everyone.
As to the RDR/GTA system - I am rather a fan of that. You can go wherever you want, essentially when you want to. You can skip right ahead to your destination, or you can even sit back and watch your entire trek from beginning to end. I love RDR's fast-travel. It didn't restrict the player in any way, while also allowing you to decide what was the most "immersive" way for you, the individual player, to get there.