My baba was a classic boomer stereotype and this was one of the things she used to say often. She also made comments about my cousin always holding / wearing her baby. She would slyly ask me if my mother grew up insecure or craving attachment because of the way she was raised. Finally one day I said to her "If she did, she certainly wouldn't say so" and my mom, who happened to be present, agreed. Never heard a word about it after that. Lol.
Definitely not all boomers, as my parents have never allowed my babies to cry, my MIL wouldn't do that either. It's horrible, so damaging to babies!