When someone passed away, we should pay respect. It's not because that person has more contributions that yours, or achieve higher than you. It's because our religion taught us to respect the life of that person in which one has no power to control. Our 'mohoing/molohing' also taught us to bow down, and pay our last respect to those who 'walk' earlier than us. We cannot actually do anything but put 'off' death, so we ritually acknowledge that we, too, will someday join the dead, Rest in Peace, Respect to my dead Homies, etc.