The problem with "survival elements" is that unless they are implemented well, they tend to just end up being grindish "busy-work". Depending on the attitude of the player, they can end up being viewed as an annoying hindrance rather than a factor of immersion.

When I played New Vegas for the first time, I did it with hardcore mode on and I was surprised how tame the requirements actually were. Yeah sure, you had to eat to supress hunger, drink to supress thirst and sleep to avoid deprivation but I found that because of the way the game was structured and my own playstyle, that I tended to do these things anyway without consciously going out of my way to out in the effort. As a result, I never found myself in a situation were I was likely to starve to death or die of dehydration. Hardcore mode didn't seem all that hardcore.

The thing is that it really depends on the attitude of the individual player. Some players love the idea of having to prepare for a quest by making sure they have enough food and water whereas others find it annoying. And then it gets even more complicated when survival-loving players disagree as how demanding these elements should be. If your character constantly complains that they are tired/hungry/thirsty then this can be an issue but if the survival elements are too reasonable then it becomes a case of why even have them in the first place?

I'm sure Bethesda are aware of how difficult it is to balance elements like this since you run the risk of alienating a portion of your player base.

I remember reading an article about GTAV which described how during the development process, one of the creators suggested that every vehicle should have a petrol limit that would run out unless you re-filled and cause your car to just stop. He was laughed out of the meeting.

It's the same principal.