Until airlines started charging extra for hold-baggage the only passengers generally having big cabin bags were those overnight business traveller (who were probably far more aviation savvy anyway). Now everyone tries to get a week's holiday clothing in the overhead locker and those bewildered annual holidaymakers are far more likely to be clogging up emergency evacuations. For all sort of reasons we should really be encouraging baggage to be put in the hold and genuine handbags and essentials to be in the cabin.