Thats been my observation too. The right-after college crowd all divorced. The only people I know who married young and are still together were the ones who got married really young, at age 20 or so, usually because they teamed up to overcome a hardship.
The rest of the crowd all got married at around 30 and are still married. Most have teenagers now.
People call them "starter marriages." Kids get married right out of high school or college, then figure out the marriage doesn't work. With no kids or any real assets, the divorce is usually pretty painless. It's a learning experience with, hopefully, no real harm done.