Sometimes what is abusive can be a matter of perspective...
Sometimes though it's as obvious as the nose on your face. The video in the OP is obviously wrong for a couple of reasons, the youth of the person being hit and the fact that someone thinks it's fine to actually just keep punching someone who isn't defending themselves. As an MMA ref I would stop a fight if one of the fighters was not intelligently defending themselves. No one should be thinking punching someone who cannot or even will not defend themselves is right.
I've never seen or heard of an initiation that was designed to somehow not abuse or at the very least humiliate the person undergoing it. At best it's pointless, at worse it's abuse.