There are so many "currencies" in the world, dollar being the most well known. But in order to change from one currency to other requires many road blocks set up by technical, national, financial entities throughout the world.
Each road blocks requires a fee of some sort, such that in some countries sending money can be charged a fee of 30%. This is of course inefficiencies to make fat cats happy.
Now we have the technologies to remove these inefficiencies to benefit people all over the world. Something Bill Gates is talking about.
We need "People Money" not only to remove inefficiencies, but to make the better world by revolutionizing the financial systems to make transactions easier, faster, and securer.