A good post from 2010 (it was already obvious to many Blackberry would fail/go bankrupt then):

http://mobileopportunity.blogspot.ro/2010/10/whats-really-wr...

Blackberry's biggest mistake was blinding itself to the truth with "good financials". It was right there in front them of that they were losing the US and Canadians markets - way back in 2009, if not earlier than that. Those were Blackberry's core markets - the markets in which its brand was the strongest. And it was losing them!

But it refused to see it or accept it because at the time most of the people outside of the U.S. had barely heard of the iPhone, perhaps in a TV news story, and Android was barely a year old and nowhere close to the iPhone sales numbers.

But in those markets Blackberry had some inertia - people had heard of Blackberry from a few years back, and it was growing in popularity thanks to BBM. But the point is this was irrelevant.

Blackberry should've known that if it loses its core markets, where it's loved most, and where people had bought Blackberry phones for years, then it would only be a matter of time before it would lose the newly acquired emerging markets, too, where it's brand wasn't even that strong.

Because of this "success" in other markets, Blackberry dragged its feet when it came to building a solid touchscreen smartphone platform. Perhaps, in its own arrogance, it even thought that the success in the new markets is "confirmation" that Blackberry was here to stay, and those new "touchscreen fads" were irrelevant. But all it had to do is realize that it if it was losing its most loyal market, then the other markets were being built on quicksand.