Why would someone desire a pension instead of a 401k?
It seems to me that the employer will fund it either way. Maybe I'm misremembering stories of pensions being mismanaged and lost. I think the most important thing is that the employer actually does something to fund a retirement, in my way of thinking the 401k approach puts me in control of the money so I don't rely on someone else to not fail.
Whether it's promised bonuses, stocks, or retirement funds, my motto is always "show me the money", and I'll believe it when it's in my hands.
Military and government can retire after 20 years. So if you're 18 when you start college, 22 when you finish, and you get a commission as an officer, you can easily hit Major by retirement age at 42, and receive like $6000-$7000 per month, plus benefits, for the rest of your life.
Even before, people would often work later into life. Many people are fucking terrible with money and if spent poorly, you may need a job even with the pension.