Both of which conquered their respective markets with their "terrible management". Perhaps you have a chip on your shoulder, but your argument is self-nullifying.
Nortel headed to the shitter, it should be noted, when they recruited management from Motorola.
RIM went into the death spiral because they were committed to keeping BBM as their cash cow long after the world had moved on. They saw themselves as their own competitor, which is how you end up with products like the Playbook missing basic communication functionality.