It is worth recognizing that Microsoft tried to recreate the PC ecosystem with mobile. The idea was that hardware makers would accept making a large payment to Microsoft for the software and then go and compete on the same type of playing field that was already troubled in the PC market. There were many reasons this would not work (ARM was not as standard as Intel, economics of the phone sale were not like the transactional nature of the PC market, availability of software substitutes already such as Symbian, and so on).
Compounding all of this was the aversion to building hardware which even at the time was proving to be the successful path (Palm, Sidekick, and of course Blackberry).
The economics of Blackberry proved quite challenging to deal with as they were making money on the hardware transaction, the customer’s server side, and on the carrier service side. That was quite magical and led to a “have it all” point of view, so long as there wasn’t a hardware component ;-)
There are many software (or software+hardware) technology issues as well that aren’t touched on. The product design, runtimes, experience, focus on stylus v. touch, and API were also never really competitive once Blackberry emerged.
So while this is a good list, there wasn’t really a front where there was a solid lead to build on — hardware, software, service — unless you just assume a complete revisiting of all the choices at the time and chose some asset to build on.
I was completely addicted to Blackberry from the first time devices arrived for testing with Outlook — it was a transformative device. It was clear it was a thing. But in all fairness, I (along with many others) failed to see the stunning breadth and growth of what was to come. My great friends in Japan tried many times to convince me of what was to come when they showed me their DoCoMo iMode phones but even that did not prove compelling enough. I used to argue that point with them from my Blackberry pager device!
Even had Microsoft chased and won versus Blackberry, it should be clear the disruption from having built a better Blackberry would have still have taken place when the iPhone arrived. There is no reason at all to think that a better Blackberry would have resulted in an iPhone, app store, touch UI, fast route to 3G, or more. Too many of the starting points were not what ultimately succeeded or they were vectored differently that was came to be.
I wrote this post a while back and much of this applies to what was going on at Microsoft at the time, Disruption and woulda, coulda, shoulda.