Do Android, iOS and Other Mobile Operating Systems No Longer Matter in Mobile?

If the actual article http://www.visionmobile.com/blog/2013/10/how-to-win-in-mobil..., is correct, why has Blackberry fallen so hard when you can run Android apps on it?

I don't think people actually by a device because of the apps that run on it. They are influenced more by advertising and friends.