I can understand why it's annoying for some people, but at the same time only a few of the 40 ubers are purify bosses and the content is highly optional. Saying that the game is unplayable because of that mechanic is stretching it quite far.
Some might argue that it could use tweaking i.e make the projectile move a bit faster or the bosses take less hits, but imo it's good there are some really tough challenges in this mod and making it easier might be the wrong move. I have seen people doing those bosses in 20-30 mins, which isn't alot of time if you consider how long mythic raiding in wow can take and there are no guaranteed rewards in those aswell.
pretty much these:
Glow-Worm wrote:Purify was meant for strategic endgame fights. It would be kinda dumb if you could faceroll every boss with BiS gear.
SeaWeed wrote:Purify just means that your damage output is being approximately set to a constant. There is no "bis" gear for every content in median, and there never will be. Deal with it.