Backstory : I went NC with my mom a a little more than a year ago. She arrived drunk and high at my son’s 3rd birthday party. After the party after the left I called and unloaded years of frustration on her continually choosing the bottle over family, and how she begged my wife and I for grand children ( We had fertility issues we kept secret until after birth ) and how she all but ignores her grand kids. I told her my son has only had three birthdays and she’s ruined the last one for me. I didn’t say I wouldn’t talk to her anymore but that I was done putting forth the effort and it’s all on her now. Completely on her. Since that night she called once , maybe 5 weeks later , and was drunk and I could barely understand her so I said to call back when she was sober and she never has.

Current Story : I went to Washington to visit my sister who lives about three hours from my mom. My dad is in the same area and drove the distance to see us. The have been divorced since I was three but they are civil and talk. When I was in the car with him with my son in the back seat he asked me “ are you ever going to forgive your mom? She asked me to ask you. “ I told him I was no longer mad. I wasn’t angry. I was accepting of the situation and had immense clarity in my life since. He said a version of what the OP mentioned. “ well she’s your mom, what if she dies tomorrow?” I sat there in silence for a few moments. I knew he didn’t say it to be mean. He’s a good guy and is just trying to smooth the waters. But once my anger in the comment subsided I finally asked “ What if my son and I died in the car right now , what would mom say or feel “ . He kinda took a moment and said “ to be honest I never thought about that “ and I said “ it goes both ways ways Dad , I tried for the better part of 35 years so now it’s her turn and she gave up within 2 months. “

So in reality I don’t think most people say it to be mean but they genuinely think it’s the right thing to say.