I think context is important here. Some considerations for people who are working or have worked a forty hour week:
-- Did you wear a nametag with your name, or another person's name on it? Was that name Earl?
-- Did you have a union representative named Tiny? Was there a tacit understanding that were you to work one minute above forty, Tiny and his friend Earl would break your legs?
-- Did your job have room for advancement to a position that wasn't your existing position with the prefix "Senior" or "Shift"?
-- Was your job "freelance" or "flextime"? Was "freelance" or "flextime" a euphemism for "Next week, I may be paid in magical beans, or not at all"?
-- Was your job one that you pursued a higher education to specifically avoid?
I'm not saying that there aren't great jobs out there for 40 hours and under. There are. But only in certain industries, and rarely with much room for advancement. Now you might say (and indeed some have said), if you're ambitious and you take the job that means working incessantly without adequate compensation, haven't you done that to yourself? Why yes you have. But the internet is the place people go to bitch about things they have done to themselves. That's what makes it so wonderful.