Some did.
However, we have a more vulnerable population now in that we have a couple generations of immunodeficient chidren who survived and grew up into adulthood ONLY because antibiotics were discovered and helped them survive.
And we have a population of people taking steroids for asthma and COPD, and cancer chemotherapy, and organ transplant recipients. These therapies didn't exist back then and these people would have died of their primary disease.
Finally, one got vaccinated in childhood when the immune system was at its peak and able to respond at maximum to the attenuated virus entering the system. A lot of the people we are going to vaccinate are adults now, who will have a higher rate of ill effects. For the same reason that chicken pox is a more serious disease in adulthood than childhood, it is riskier to vaccinate older people. Remember Patsy Mink?
Thus a higher percentage of people now will be at risk for greater problems than was true in the past.
This is a reality we have to try to cope with and try to minimize as best we can.
Is the risk to theses vulnerable people any more from a smallpox vaccination than say a flu or pneumonia inoculation?
Childhood diseases are always and have always been worse in adults, than in children. Lord Byron died from measles. Male adutls, who got the mumps, were made sterile. What is forgotten, or unknown, in all of this hysertia, is that children used to die / be maimed, from all sorts of things, which people, in the USA, no longer get. All of us, children AND adults, now get strange illnesses, because people now live longer and don't get things like whopping cough, measles, mumps, etc. !