1. Loads of pent up historic demand 2. Work is complex, sensitive and physical. 3. There's more history every day!
The church historically absorbed excess males in this way and gave them a dignified purpose in life, it's not a crazy thought at all.
That was often a consequence, but in general it provided an alternative pathway to male success in life and a means of advancing through a respected status hierarchy that did not depend on the traditional markers. Something sorely lacking today, when even outside the question of inheritance you are faced with the near impossibility of achieving the economically independent and socially valuable life that your grandfather or father had by simply working.
Those that don't most often have decided to set an unrealistic definition of economically independent and socially valuable life. Their grandfathers never had it that definition, but they somehow think their grandfathers never struggled and otherwise had it a lot easier than their grandfathers really did.
there is a second group that has decided it is impossible, and thus refuse to try.
Don't get me wrong, bad luck happens to everybody. Most don't get luck so bad they can't recover though. Some get worse luck than others.
In general set reasonable goals and you can achieve them.
I don't think it's that they think they never struggled. It's that the struggle resulted in something. Work hard, because it will probably earn you a promotion. Put a little extra on the mortgage every month, because you might be able to pay it off one day. Save a bit for your kids college, because then they'll be able to afford it. All of these things are practically quaint at this point. Some people can pull it off, but it's the exceptional case now, not the median as it once was. Increasingly you need a 90th percentile 21st century income to get a 50th percentile 20th century life.
Meanwhile plenty of people (though a minority) are doing it right now.