> don't particularly understand why it would be worth defending or even necessarily better than minority rule in the first place.
The word "minority" conjures up images of the oppressed, but through most of human history, the minority have been the oppressors. The majority were, historically, ruled by the will of a minority of people that made up royal families, etc. Saudi Arabia, for example, is a society in which a minority rules the majority.
Now, of course, in a democracy the majority can use violence to suppress the minority. But that is in fact the bulwark of democracy: the majority using violence or the threat thereof to suppress royal families, warlords, etc. And while ideally the majority does not do this, oppressive rule by the majority is almost certainly preferable to any situation where the minority is in power.