AITA for saying my brother's step kid was his "only chance" at being a nice dad?

I (28M) am the youngest of three brothers. Our parents died within the past year. <br><br>We all have very different lives, and have since we were kids. As the result of being born premature, I have a lot of health problems. My oldest brother, James (40M) is very wealthy, being a partner at a successful brokerage firm. My middle brother, Richard (38M), is a college professor. <br><br>Growing up, James was a bully. He was extremely violent and sadistic. To give you and example: when I was 12, I had to have major spinal fusion surgery. I was bed bound for most of the summer. My brother came to visit me from his college dorm. He asked me to read a short paper he wrote for one of his classes. His paper was on why he believes euthanasia should be legal for children with disabilities. <br><br>Fast forward, James has a 4 y/o daughter named Madison. She is as sweet as can be, and she's totally unaware of how horrible her dad is. I've distanced myself from him and don't really keep in touch. It was sad to not have a relationship with him, especially after our parents died, but I don't feel comfortable allowing him into my life.<br><br>Richard, however, has a step-daughter (19F). She's a sweet, athletic young woman who was born with severe physical disabilities. She cannot walk, has terrible scoliosis, and has other issues. As a result, she does not speak. She communicates by using flashcards with words like "yes", "no", "bathroom", "food", etc. She is in college to study physical therapy, so she can help other people with disabilities. She is very intelligent, and has learned to more easily communicate by using full sentences with her flash cards. She is also on TikTok, where she shares videos about disability acceptance and accessibility. The TikTok has been a great way for her to express herself, as she feels she can say things she wants to say without people judging her the way they do in real life. <br><br>With our parents passing, Richard and his daughter Rose have been raising money for disability awareness. Her TikTok has helped with fundraising, but it has also drawn negative attention, including from James. James thinks it's inappropriate for Rose to speak about disability awareness on her TikTok when she herself has a disability. He said he's concerned that his daughter Madison might see Rose's videos and become confused, or start thinking she is disabled too. He was adamant that disability is a personal issue, and it should not be discussed openly. <br><br>Rose heard about this and confronted James, posting about it on TikTok. She said that him wanting to hide her disability was able-bodied saviorism and ableism. This made James incredibly angry. He wrote her a very nasty message saying she was making a fool out of herself, and telling her she was not entitled to opinions because she "can't even talk". <br><br>I saw this exchange on TikTok and snapped. I commented, saying that James was the one who was making a fool out of himself. I apologised to Rose for his behaviour, and said that he'd been a bully his entire life. I said I'm sorry to my niece for being related to someone so awful, and that James was most likely jealous that Rose is beautiful inside and out, with a big heart and a passion for helping people, while he himself is ugly, inside and out, and has always been cruel to others. I said that he would be lucky if he could spend half as much time thinking about how to help others as Rose does, and that "maybe this is your only chance to be a decent, caring father". <br><br>James was furious. He called me, yelling and asking how I dare question his parenting. I told him he wasn't a parent, he was a sperm donor with a DNA connection to his daughter. He has never been a good father. I told him I was raising money for disability awareness, too, and I was going to continue "talking about disability" openly. This just made him more mad, and he hung up on me. <br><br>AITA for saying James is not a good dad and calling him ugly?