The Boyds stock does not have those pillars. The action will sit on the top of wood that does not have a perfect (though likely adequate) fit. As the wood swells and retracts under various humidity and temp conditions, it can impose stress or binding on the action. By adding pillars you prevent the wood from compressing under stress of the tightening of the screws and deforming the wood so the torques remains consistent. As for the bedding, you remove enough wood so there is a good, solid bedding matrerial base that the action sits on and resists the wood's changin shape benieth it due to humidity or lack thereof, etc.

You factory plastic stock should not need bedding.