Its cuz ppl want to be the jack of all trades.
If you know how much grief and terribad rng luck will come from this, why even bother and pursue it? You are just beating urself up over a small thing. You probably wouldn't even use those alt classes for content u r unfamiliar with.
Sure it gives you more options but those options die here as the Atma quests and 2nd coil rng are here to make sure of that.
The only thing that is going to save u are the sol tomes and tidal weps.
But atma and coil brings out our worse halves as its mind numbing rng kills our gear progression's libido!