Simply put, charitable giving isn't a zero-sum game; people who don't donate to/through Watsi might not donate at all. It's intellectually dishonest to argue -

Simply put, charitable giving isn't a zero-sum game; people who don't donate to/through Watsi might not donate at all. It's intellectually dishonest to argue - without substantiation - that Watsi diverts funds from other charities. We can argue about improving their efficiency, but the zero-sum argument is counterproductive.