I understand the implications and I think it should be the person’s choice, not the parents but as a person with a penis whose parents had him circumcised, I don’t think about it ever really and it doesn’t affect my day to day life.
In answer to your questions, I’m not sure why they did it.
Both of my parents worked in health care and in the US, circumcision is treated as preventative treatment for things like UTIs and other complications.
At this point in my life, I’m not planning on having children. Would I circumcise them? Probably not as I think it should be a personal choice.