Torghast is same as the magetower in Legion, instead of blaming themselves playing like shit they blame tuning. Some classes have it harder, but it's doable.
Tell that to my mage. No real way to heal besides anima powers, but you can be smart about them. It's not like it's not possible to be fucked with RNG, but it's players choice to pick dmg over "your fire blast launches enemy into the air" which is insane boss cc.
95% ?
Well, if we are pulling numbers out of our assess... 95% players who can't kill the bosses are not planning to synergize their powers in the long run and just pick "this one looks cool" and then complain.