We should encourage people with rare generic deceases to use fertility treatments that filters out particularly bad genes; or adopt children instead.
Where does it end? My Aunt had cancer. My father high blood pressure. I think one uncle on my estranged mothers family was quite mad.
Am I allowed to procreate? Who draws the line on what is an acceptable level of hereditary risk factors?
That is the line. It ends there.
By the way, there are a ton of people who actually do believe that taxes are a slippery slope to socialism! The employment one is funny. But I think there are people who believe consumerism or capitalism is a slippery slope to criminal activity like prostitution. People are so funny.