They didn't. What they needed was to improve software and keep new devices and pushing for touch, pushing for a better operating system. I mean, we've still been stuck with the ancient BB software for YEARS until FINALLY QNX came out this year. THIS YEAR.
Competitors have had modern operating systems for over half a decade. Blackberry couldn't keep up. How I wish they had; the keyboard is one of the biggest selling points I can think of. I'll miss them.
I predict that by this time next year, Blackberry will cease to exist as the company that it is (or was). It may be a subsidiary, but you can expect that we're not going to see any innovation from the struggling company anymore.