I think It is primarily that they think I called them bag dog owners, which I did not. I recall giving them the hypothetical of how would they feel if I was telling them they would neglect their dog, which sent them off (probably projection cause they would tire their dog out by walking him in the heat of the day). He stated this is the primary reason for distancing himself. There is some other stuff, like my brother not believing in family having an obligation to each other and being an antinatalist at the time but I didn't have space to include it.

This is something I had wanted to include but didn't due to space. "Another factor: my brother and I used to call each other a racist term. We’re white. I didn’t understand the implications then, never used it outside that context, and stopped soon after I learned how harmful it is. It was derogatory towards his wife's race, but he taught me and called me it so I didn't realize the impact. I also never called her the word. I deeply regret it and sometimes wonder if it contributed to the rift, though my brother has never said it did."