Post WW2, we had gradually managed to build a less violent society, and at some point, some CEOs decided: "You know, the Ludlow massacre and the Bisbee deportation were not that bad". And now, we get the pushback, where some employees think that murdering a CEO in the middle of Manhattan is fair game.
Rules didn't disappear. But people are more willing to go to conflict about them.
Welch wasn't a problem until what he feared, backlash from people who had been around for the last cycle of cruelty precipitated by his ideas, sufficiently died/attritioned out.
Give Going Postal: Rage, Murder, and Rebellion: From Reagan's Workplaces to Clinton's Columbine and Beyond by Mark Ames a read.
He does an excellent job at laying out the pedigree of thought from slave/plantation management to modern American management theory, and charting out the trends and consequences that arise from political shifts in the equilibrium between capital and labor.
https://www.amazon.com/Going-Postal-Rebellion-Workplaces-Col...