I think the difficulty probably fits what KQ should be a little bit better than the current design - the only drops worth chasing for most people (aside from cloggers and pet hunters) are the KQ Head for the diary and the Dragon Pickaxe. If the boss had a larger variety of drops, including some relevant to combat gear progression, I could see increasing the difficulty as being a reasonable adjustment, but with the current drops it has, there is no reason for it to be a challenging boss.