In a factory in 1965, maybe, but no good employer is going to fire someone for making a mistake, no matter how costly.
Depends on the factory, and I doubt it's much more or less likely in the 21st century than it was in 1965. In all times and places, you have enlightened and unenlightened people. In all times and places you have good and bad leaders.
"In every time, in every place, the deeds of men remain the same."
Citation needed. I'm pretty sure there are fewer war deaths and fewer kittens burned for entertainment per head now than 200 years ago.
Yes, there is less bad stuff, but the quote says nothing of frequency.
The problem with your attitude is that it's based upon a premise that is almost never true: that screwups are caused by incompetence, and that they have singular (or overwhelmingly singular) sources.
Neither of these assumptions bear out in reality, and certainly not in our industry.
The vast majority of downtime events trace back to systemic failures, not a freak event, and are more often catalyzed by momentary lapses than long-standing incompetence. Do we penalize the tech who clicked the wrong link on a dashboard, or the guy who wrote the dashboard such that a critical action contains no safeties or confirmations? Or do we penalize the manager for not having any established documentation on protocols surrounding triggering critical actions?
The only reasonable stance here is to collectively take responsibility for the failure. It may feel good to hang someone out to dry, but in all likelihood their failure was only the final link in a long chain of failures that extended well beyond themselves.
You root cause what led to the event (going deeper than "a tech clicked on the wrong thing"), and you fix the root cause, and you move on.
A team of good people should learn from their mistakes and reduce hazards along the way. But bumper bowling is no fun for experienced players. It's a balance, and it does tend to shift as a company grows.