Why people sponge off mommy well into their 20's?

I am in my early 20's and I pay for my car (put down payment, no co-signer) my apartment, bills, food, wash my own clothes etc. But I see that a lot of people now always rely on mommy. For instance they may say "I pay for my own car"(but that's after momma co-signed for them at 3.2% interest) or they can only afford 1 bill cause momma and pappa pay for the rest. Since when was it ok to hang onto your mommas **** for so long. I often wonder what would happen to these schmucks if all of a sudden you could not get istance from mommy. I bet that 90%+ would not have a car, apartment and would be living at home. I feel that when you are 16 its time for a job and 18 is time to realize adulthood. What do you feel is causing this "mommas boy syndrome"?