Why Can't Someone Donate Using the App?

 "The nonprofit world is stewing over the ban Apple has put on making donations on the iPhone via charity apps."
Original Article 

Many non-profits have made apps for the IPhone, but not even Apple knows how many different ones there are. But Apple has made it so that someone who has the app on their phone can not make a donation to the non-profit using the app. If one wants to make a donation, the app leads them to the non-profits company rather than making the donations through the IPhone app.