I heard that blackberry has completely separate teams that work on each OS subrelease, meaning that the 4.6 guys don't talk to the 4.7 guys, who didn't talk to the 5.0 guys. Developing anything for the blackberry over more than one OS release is a complete and utter nightmare. Even after that, you have to worry about carrier differences, BES vs. BIS devices, and a ton of other things.

In the App driven world, BB development cycles tend to run 1.5-2x longer than iOS and Android because of the inconsistencies, even for seasoned devs, at least at my last company.

BB will die because nobody will develop for it.