Have you even played Path of Exile? People LOVE that shit. Endgame bosses hit you for integer multiple of your HP, the only way you survive is through theorycrafting how to mitigate it (or be one of those losers who has to follow a guide)
Hell regular bosses LOVE massive damage spikes. I'm with you that it pisses me off and I since left for greener pastures (Grim Dawn)