Complex and deep != hardcoe. In fact they have nothing at all to do with each other. TES does not feature any sort of required eating or sleeping mechanic, your character tends to start out with some decent gear or funds from the get-go, and either everything's only as strong as you in the beginning (Oblivion) or you become a demi-god after a dozen hours of gameplay (Morrowind). Diseases have been nothing but nerfed since Daggerfall (where they could kill you). Probably the worst thing an enemy can do to you is damage your attributes, which are just a pain to heal and little else.
Name a few things you think are hardcoe in TES.
Indeed. Which is why I'd rather they not spend time developing a save nuker mode for the minority of players who would use it, when saves can be easily nuked by the players themselves. I won't enjoy it, and you can do it on your own.
I don't need perma-death to tell me not to rush a TES game. And I don't see how it could possibly add longevity to a character, when that character gets deleted as soon as you wander into a hard dungeon prematurely.
Yes. "I better not enter any dungeons until I'm level 30. I wouldn't want to lose my save files." Fun!
Like what, the nuking of a save file?
It depends on how you interpret what hardcoe is. However, this is completely irrelevant to the topic... If you want a topic about that, feel free to make one.
You can say that, but there would be no benefit to the player to just "do it." BGS would have to give those willing to do it incentive, and wanting to actually complete the challenge. It's like eating, drinking, and sleeping in BGS games. You can choose to do them, but unless there is an actual incentive to take advantage of them, you won't.
The likelihood of wandering into a hard dungeon probably isn't likely, as one is likely to come across harder NPCs before they get to such a section of the map.
Sarcasm aside, as I stated before, this isn't a system for everyone, hence "hardcoe." I would expect most to not even meddle with such a mechanic. But that doesn't meant that BGS couldn't easily implement something in to give those that would actually like the challenge.
Like if you are in a hall surrounded by Dark Brotherhood assassins and decide to throw a fireball at one of them for kicks... Players will actually have to show restraint and rationale in what they do. I guarantee you playing Skyrim with permadeath would be completely different from playing without it, and not because it's "frustrating." It would offer a gaming experience few have actually experienced, and would be there for those willing to make the risk. It is hardcoe for a reason.