Think about it - no steam engine, no coal power, no industrial revolution, no greenhouse effect. No railroads in the 19th century? No railroad tycoons. No railroads in Nazi Germany? Much less efficient Holocaust.
Locomotive travel and its consequences have been a disaster for the human race.
I can think of at least 3 separate eugenics style things it could be used for, but I'm sure that's also a lot of people's kinks so who knows.