> They just were severely undeveloped people, who were reactionary and fearful.

This is an accurate way to describe my parents, too. I stopped talking to my dad after my mom died for many reasons including the above. Although I recognize they did their best, I just stopped answering phone calls one day. I didn't think about it; it just came from immense emotional pressure.

In retrospect, it was the right decision for my circumstance. I do appreciate your approach to deliberately keeping your parents at arm's length without cutting them off, though.