Really thinking on that, this is going to be hard to answer. I'll give it a shot.
We start out with a large population of humans with different ideas on a subject. Let's use an example: how to govern the landmass full of humans so it doesn't descend into violent anarchy. Generally rising to the top is either a minority that manages to convince the rest that they are more qualified to lead and make decisions, or the majority who agree on a method and conclude being the majority as reason enough.
But why such value on the majority? I suppose if you put it down to smaller sizes of humans and in a more tribal setting, if 10 people think tribe should use spear not rock, and one person think tribe should use rock not spear, the 10 people stabbed the one person with their spears, and then carried on with their business. We see less of this kind of bullying by the majority now, but there's still that hidden acceptance that majority > minority.