Why can’t my ex-husband, family and friends just accept that I don’t want to be a part of my daughter's life?

My ex-husband and I got married at 27 and at the time he was fully aware that I never intended to have children and he told me he was ok with that. I couldn’t find a doctor who’d let me get my tubes tied in my 20’s so I took every other precaution I had available to make sure I didn’t get pregnant. After 3 years of marriage I got pregnant and was determined to abort it but everyone around me especially my husband begged me to reconsider uring me I’d feel different once she was born. I ended up having my daughter , signing away all parental rights and divorcing him because I didn’t see how we could make it work with a baby I never wanted in our lives. I see my daughter about four times a month when dropping off the 5 dogs we share custody over. My family has virtually disowned me for not having any contact with my daughter who turned 3 last week. Why can’t they just understand that I don’t want to be part of her life? Note: At the insistence of my mother who adores children, I went to several doctors who all confirmed that I’m not suffering from any type of depression and am in perfect health. I just recently got a promotion with a significant pay increase and have a wonderful boyfriend of a year and just couldn’t be happier. Why can’t they be happy for me?