The difference is your brother’s birth defects effected his quality of life. The only reason I had surgery performed on me is my genitals were ’ potentially ambiguous’. There was nothing wrong with them, nothing wrong with their function, they were just different. I was mutilated because I looked different. They were worried I might be teased as a kid, so I was cut apart.
Oh, it wasn’t just the medical community. There were a doctor or two that advocated me being left in tact, but the final decider was the Church. My parents had the surgery done because of the Church. The doctors freely admitted that I was functional as is, and the advice they received from the Church was the tipping point in favor of surgery.
It’s like performing surgery to change someone’s eye-color just because a new color developed and they didn’t want them to be teased as a child, but in the process made them partially blind. What is the purpose? There is none. My quality of life was reduced because of the surgery. Not only am I essentially neuter now due to the surgeries, but I suffer frequent infections as a result.