I'd argue there's an even more fundamental reason for the hazing process, as you call it, which is that the voting system itself incentivizes negative campaigni

I'd argue there's an even more fundamental reason for the hazing process, as you call it, which is that the voting system itself incentivizes negative campaigning as just as if not more effective than positive. In other words, a dollar spent trashing the "other side" is destructive yet effective. This destroys healthy competition and encourages mutually destructive behavior.