At the end of the day, the big "problem" I see with and hear about PbtA is that the main mechanic relies on trusting your MC to know how to make Failing Forward work, to generate complications which are relevant and at least consistent with the situation if not necessarily balanced.
an explicit directive to the MC to make things shitty for the player characters, that's a hell of a lot of faith to put into the guy running the game,
I know one person who I've played with that I would maybe trust to not kill all the players an hour into the first session, whether through malice or incompetence.
It sounds like your issue is one of trust. And that's fine and normal.
I actually find that PbtA games help solve trust issues! GMs who don't like giving up control now have players that can change the scope of the game AND the world. Players now have a GM that can throw ANYTHING at them if they fail, not just some damage from a chart based on a specific threat. The GM thinks his players can POSSIBLY make as good a story as he can, and the players think the GM can't POSSIBLY generate fair consequences.
But the game doesn't play that way. You do your RPG trust fall and the group catches you.
Have you played?