Indeed, factory workers, back in the Dickensian days, were uneducated masses. As most they had a 5-6 years of schooling, but none at all was also common. They sure didn't learn rote behaviour and obeying orders at "school".

And at the same time, higher classes attended highly demanding schools, with very high discipline and demanding curriculums.

Plus, on the 20th century, mass education was adopted by almost all countries (including agriculture based ones), and it had produced people working mostly in office and service sector jobs, not rote factory assembly lines.

So if anything, it's the inverse of the "old wives tale".

(See, we can also agree on some things!).