The "undesirables" comment is a little harsh. You're taking about people who are foolish enough to trust that doctors have their best interests at heart, and get addicted.
Here’s some light reading for you: https://en.m.wikipedia.org/wiki/IBM_and_the_Holocaust
The parallels should now be obvious.
I see upon reading my OP that I did not identify IBM as a co-guilty party paralleling McKinley. My apologies.