Some, however, do. I appreciate that Bethesda included some tougher difficulty levels, but I don't think they went far enough. The game's difficulty should go all the way up to the point that it's actually impossible to finish. That way, nobody on earth will find the game to be too easy. Even with the best equipment, max spells, enchantments, skills, and perks, there should be enemies that crush your soul on the highest difficulty.
There's no reason not to include that, because some people certainly want it. Even I might have some fun tinkering around in a world like that, for a bit. It would be interesting to see how long you could last. Also, it would be purely fascinating to see if anyone comes in and complains about the ease with which they can sneak past everyone or something.