We just did this yesterday.
The answer is —culpabiltiy varies wildly.
Someone who rejects the church knowing full well what it teaches is VERY culpable, but in most cases that doesn’t happen. Given the poor teaching from parents–heck–even from Priests and often the frustrating decisions of the dioceses.
My family was affected by a corrupt diocean official who was fired for their actions.
It affected my brothers in different ways.
My eldest brother believes the issue is any sort of church goverment, so he goes to a church that governs itself.
My middle brother took on the belief that ALL religion is evil and is a hardcore athist.
My youngest brother came to terms with it by being very wary of church and he will only attend Mass on holidays because he feels safer in the crowd.
Will they go to heaven?
I don’t know. I hope God has mercy on each of them and their decisions. I do think that perhaps my eldest brother will fare best in purgatory because he still deeply desires and pursues a relationship with God.
Only God can judge a man’s heart.
For us with knowlege of what we’d leave, the stakes are much higher–but for those who have been hurt, misinformed and mistreated–God has a plan for them.