The games industry has had a resurgence of difficult, complex titles in recent years. Dark Souls, The Impossible Game, and many more have offered players exceedingly hard challenges. Why we gamers are so enthused by this type of game is up for debate. That said, there is the argument that by beating a game that is so difficult, you feel more accomplished about it.
CD Projekt Red has obviously been paying attention to gaming trends over the past few years. They're talking about creating an 'Insanity' difficulty mode in The Witcher 3: Wild Hunt that will delete your saved game upon death. This game mode would likely make enemies in the game world even stronger, making grinding for levels a necessary task. Given the size and scope of The Witcher 3, players could stand to lose quite a lot of time and effort.
Personally, I'm not sure how I feel about the described 'Insanity' mode. I'd be more comfortable losing all my progress in a smaller title, but in an RPG… not so much. That said, if this does come to fruition, it'll make for some great stories and Twitch streams.