I agree that if a person has no self control or free will then yes an option would be great. Thing is, what will stop the person from toggling it back on? That is what needs to be answered, and that is why I beleive Bethesda will not spend the time or resources to do so.
Todd Howard said something about "You don't like it, don't use it". So far nobody has proven this. The original poster ask to show that people want it, but I haven't seen anyone prove why they need it. Going back to page one and reread everything just in case I missed something.
I say it because it doesn't really add up to any discussion value. There have been many threads about fast travel before; many of them have ended in flame wars concerning the argument "if you don't like it, then don't use it".
It's a lot better if you actually say what you want and why you want it. That can be discussed. The "If you don't like it, then don't use it" can be said about almost anything.
Take this for example: You REALLY don't like the magic system that is proposed to exist in Skyrim. Many others agree with you. You really hate it because it feels so bland and it's not immersive. You want it to change and be improved.
Somebody else suddenly then tells you "If you don't like it, then don't use it". One could easily assume in this situation, that it's not really very argumentative. The person (and the many others that agreed) that didn't like the magic system would then end up with a TES game without any magic, because they didn't like it. And if they didn't like it, according to that argument, the solution was not to use it.
I say that there is more than one solution to a problem. The only solution is not "then don't use it".
As a law student, I've studied arguments, their constructions, when they are valid or not. When I applied law theories on this argument one day, I found it to be valid and logical, BUT it failed in acceptable premises, which is a must for a successful argument.
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In addition, about the "what will stop the person from toggling it back on". Somebody else said made some comparison... I think it was about this:
A person is in a cake factory. There's free cake everywhere. Everyone for take. He knows it's bad for his health though... Will the person eat the cake or not?
Implement a rule not to eat cake in this situation (kind of equal to a setting), and the situation suddenly becomes different. As a player myself who don't like fast travel, it's actually kinda tempting. I feel that a setting to actually turn it off/on would help with that.
And a setting, realistically, wouldn't hurt anyone basically. And it would take very very little time for Bethesda to implement something like this.
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The reason I didn't even post any of this in the thread is because it tends other people to lean towards this discussion anyway, which in turn leads to a discussion comparable to flame war with no real value. So please, stick to what this thread is meant to.
The examples I made here are my own examples. If you don't agree with them completely, it's fully understandable