That's a bit harsh and I think it misjudges human nature.
> Without a union, your dad would have been expected to take 30min every single time, and lose your job if you don't.
I had a summer job in a paper mill when I was 18. One of my earliest tasks was to "sweep the mill." The entire mill, which was HUGE.
I started sweeping at 7AM and by about 9AM I had completed the first floor. I was on my way to floor # 2 when an old-timer pulled me aside and said, "Hey. Don't work yourself out of a job." Then he and various other old-timers showed me places where they hid and took naps throughout the day. I decided I did not want to be the goody-goody college interloper, so I took a few naps myself that summer.
The kicker? This was a NON-union mill.
My point is that many of those jobs are shitty and unpleasant, and people do what they can to alleviate the unpleasantness of it all--with or without the union.
As far as not working your self out of a job, its true, there will always be a balance between working your ass off, and spreading out the work, but its also heavily dependent on whats expected of you: if you're only expected to complete one specific task in a period of time, there is no gain in getting it done as fast as physically possible.
Believe me, your bosses knew the oldtimers were taking naps, and it clearly wasn't a big deal for that employer.