Because you use cheap spoons. You, your parents, or whoever bought your spoons bought cheapass spoons, spoons that were stamped out of metal instead of forged. Spoons you get for pennies a piece at a dollar store. Spoons they use at cheap restaurants and diners. Nice spoons—and I'm not talking terribly expensive, just not bargain bin—are forged, and they don't bend at all. It would break before it would bend.
My silverware, which is a service for 12—three services for four, actually—that I got for something like $80 or $90 total at Target, they're forged stainless steel. They're weighty in your hand and you can't bend the spoons, the forks, or the knives. The spoons are sturdy and stay straight. The forks' tines never get bent.