You never heard of OSHA, NLRB, the various labor laws and last but not
least a very litigious society with lawyers trolling for clients every
day. Carnegie is not sending the Pinkertons in to shoot strikers, you
don't have kids working in unsafe conditions and putting in 72 hours a
week for base pay.
I think I know a bit more about the real world of labor law and what is
enforced and what isn't, generally, than you do. Most of the teeth in
many labor laws have been excised, and the NLRB is only a shadow of what
it used to be.