Because, of course, Mendelianism was much more the proximate cause of the modern eugenics movement at least according to many sources.    From Wordnik.com.  [Dr. West, meet Dr. Tinkle, Creationist eugenicist - The Panda's Thumb] Reference

There are dozens of theories, -- mutation, orthogenesis, Weismanism, Mendelianism, etc.    From Wordnik.com.  [Evolution An Investigation and a Critique] Reference