I think the point of difference is that (one) you don't die in sports, you are only injured - even if sometimes those injuries can be permanently crippling, and (two) as you say, avoiding getting hit is part of the gameplay of sports. But in a game like Dark Souls, dying is an expected part of the gameplay mechanic. They even called their special edition "Prepare to Die Edition". The gameplay loop of Dark Souls is that you will die, but each death should be a learning experience. The narrative of the game actively supports a cycle of death and resurrection - basically the story of the game is that people who are dying aren't staying dead, and are coming back to life as the undead, and this lack of death is causing a slow rot and stagnation of the world. You play a character that is undead, so there is no "fail" death state in the game - every time you die, there is an in-game narrative as to why you just come back.
What Llamadragon was saying is that it would take a special kind of someone to play a fully immersive VR experience that transmits the pain of literal death fairly realistic that has the same "prepare to die" gameplay setting of Dark Souls. Imagine going through the realistic sensation of being stabbed to death, burned to death, crushed to death, torn apart, etc. over and over and over and over and over and over and relishing it as part of the game.