I have made the observation that game developers must be very, very careful when balancing the hardcore, extreme, ultimate, whatever you call it highest difficulty level. If you make it too hard, players complain it's unbeatable. If you make it too easy they complain there's no challenge.
But if you make it just right... If it is just right then masses of gamers will spend YEARS playing it over and over, refining strategies, making spreadsheets of armor and weapons and tactics, arguing with each other over which stats and strats are best, getting really upset when people disagree with them... I mean if you think people get mad when they are cut off on the freeway, you should see the tempers flare when you say you have something better than somebody's pet strategy on a video game.
I still can't get over this. There are people who take great pride in their ability to figure out and take advantage of a video game, a system that was made to be beaten. It boggles my mind.