Why would anybody entitled to free bags inconvenience themselves by checking bags? Conversely, the guy who has to pay for bags isn't going to make a fool of his own wallet.
This is a great idea if you want to schlep around suitcases full of books and wait at baggage claim for the bags to arrive. On the other hand, if you aren't a minimum wage worker and value your time, spending 30-60 minutes waiting in lines to check and claim bags is both foolish and juvenile.
DL, I am certain, has accounted for the possibility that there are people out there who never have or want to grow up. There aren't enough of them to make a difference.