It isn't too surprising - the first popularly wasn't because of sensible "permanent reputation effects" or similar but scare mongering that giving your state and real first name was a sure way to get raped and murdered. Even sensationalist press couldn't find enough to spam even with fabrications like Nintendo DS's pictochat being a pedophile nest and it lost the new and scary factor. So between that crying wolf and the trend following and desire to be famous the shift makes sense.