So it was written and sung ironically. Malcolm Douglas says so and he's usually right about this stuff. I'm still not sure how anyone just hearing the lyrics would have been "stupid", to quote someone else, not to recognise the irony.

To return to one of my original thoughts. It must be quite wonderful for the writer and performers to look at someone in a crappy job, working for a pittance, and afraid to complain for fear of the sack. They can boast, "I'm partly responsible for that. I did my miserable little bit to undermine the trade unions."