We manipulate people all the time, our parents (and children) included. Guilt-tripping, appealing to God, to their sense of self-worth, you name it.

Yeah, that's why I said "purposely and consciously".

One of my parents was guilt-tripped a lot by their mother, and as a consequence deliberately taught my siblings and I to identify and be immune to guilt-trips while we were very young (method: attempt to put us on ridiculous guilt trips, slowly reduce the ridiculousness over time. It was very effective). Maybe this explains why it feels evil to me...