Its like saying that doctors/dieticians are abusive when they say that someone needs to diet/change their lifestyle or they'll likely die.
They aren't making up the 'rules' governing healthy bodies, but they are helping people be the right side of it.
In the same way, if you truly believe that some people are going to heaven and others hell, because of what's written in the Bible (or any other Holy Book), then you don't make the 'rules' but you are keeping people be the right side of them.
I have very fluctuating beliefs and I've been on both the Christian and atheist side.
What I can say though is that if I were God it's not the system I'd have in place. Equally l think it would be an awfully church that truly believed people would be condemned to a future of suffering, who did nothing to try to stop this. If you love your neighbour you don't want them to suffer .
So I don't think it's the churches that are abusive in preaching this. You could argue that the abusive bit is a LOT higher up...
This is the bit I struggle with, why would a loving God have such a horrible system. But equally, I accept that we don't know everything and that if there is a God, and this is the 'system', then either there are things beyond even God's control, or maybe God's character is different from the one we are told. Anyway, that are the ramblings of a person who kind of believes in God but isn't sure she likes God right now.
To blame churches though is wrong. If you knew a bomb was about to go off and were yelling at people to leave or be blown up, it's the bomber who is in the wrong, not the messenger who is trying to save people.
Ps: most churches thankfully downplay the hell bit as it's horrible, unhelpful and emphasizing the positive is far more pleasant for everyone.