They did in the early 70s. My mother got rhogam after I was born in 71.
I do think there is a strong, but probably not singular, environmental component at play in expressing whatever genetic tendency there may be (which may also not be singular). It would explain a lot of rising phenomena: ASD/other neuro disorders, autoimmune disorders, fibromyalgia, etc. Things that were unheard of - not just because of lack of label - in our grand parents' or great-grand parents' - generations.
My kids are all NT and healthy overall and, honestly, I sometimes wonder why. What sets them apart? I doubt it's something we control, simply because we can't control everything in our environment, and I know plenty of people more conscientious than I who have one or more kids with one or more of these issues.