I just don’t understand

Every time I get in an elevator to go up to my client office on the 8th floor, I wonder why. There is a sign that says "Maximum load 1000 kg"(最大積載量). Why do they always put the signs inside where it is too late to do anything about it? And what are you expected to do with this information anyway? Are you supposed to turn to the other occupants and say, "I believe I'm about 60 kgs. How much do the rest of you weigh?" If you get answers do you bother summing up all the weights in your head? If it turns out to be overweight, do you ask the heavier people to step off?
There are so many things I don't understand.
This reminds me of one thing. It is said that the world has lost thousands of trillions of yen due to the economic turmoil triggered by sub-prime loans. If someone loses money there should be others who earn that money. Where has all the money gone?