You could just as easily say: "People aren't pushing themselves anywhere close to their limits. If you look at the extremely obese who eat jars of mayo in one sitting or consume tens of thousands of calories a day it's evident that human limits are far higher than what the average person is willing to endure. For the average person they should probably be eating way more."
What is so intrinsically good about reaching one's limits?
There's definitely value in getting out of your comfort zone, but that doesn't have to be hard. IMO it's only worth pushing yourself hard if you really believe in something. Don't do it just because others are pressuring you to do so. Rest when you need it.
I'm saying that the average person could easily push themselves more in the athletic realm. If a dude has been going to the gym for a while and can't bench their body weight or run a few miles they're probably not pushing themselves at all.
This is because that way it is healthier in the long term. The goal isn't to be able to lift a lot in a short period of training time. It is usually to consistenly stay healthy going forward.
But again, that's just my experience. I disagree with you anyway, I even think it would benefit the workforce if there was a third "weekend" day. I think that that would reduce stress and thus increase productivity.