It is human nature to get one's bags ESPECIALLY when passengers know they are unlikely to see their belongings again. This is not stoppable no matter what laws are made or actions taken short of machine gunning any passengers exiting with luggage.
The ONLY way to stop this behavior is to :
1. Ban all carry ons larger then a coat, attache , purse, ipad, (child seat, wheel chair excepted). Basically non essentials.
2. Demand everything be checked in outside of above items. If passengers must pay, then they must pay.
3. Make these requirements uniform for all airlines carrying people.
Having minimum carry ons will also streamline customers going through security. And seating passengers will be much much faster as well.