Well its the only type of difficultly you can do in a gcd game as you have less control the bosses have to be predictable and do the same thing in the same order. its not like action games like dark souls for example sure you can memorize all the different attacks that the boss has but the boss is reacting to you as well its not going to do its short range attacks if your far away from him the entire time hes gonna react to the situation at hand. works really well in one on one fights. How would that work if the boss has to react to 8 people or 24 or just 4 it just can't work in this type of game. so unless this game abandons its gcd and takes on a more action game style non of these games will ever be hard. hell the hardest part about raiding in this game is finding 7 other people who play the classes needed and can be on at the same time a few hours a week with you.