This. I feel like the Blackberry = enterprise argument was always a cop out because before the iPhone, Blackberry was the device that all the cool kids wanted to own. It was a status symbol. RIM's greatest mistake, IMO, was that they had the consumer market and didn't even know it. RIM pigeonholed themselves as the go-to device to respond to work emails at 7pm during family dinner.
...I think everyone in this thread should state where they live. I am a German and I've only ever seen them in business circles, and they were certainly cool among business students (which are "cooler" than engineering students to begin with); however in Singapore I still see many people typing away on BB's in the subway. In contrast, I haven't seen a single one in Taiwan, ever, probably because they are all QWERTY/QWERTZ?
I don't buy that they ever had the consumer market. They certainly had business going for them thanks to their enterprise server. That was their market and they knew what it was doing.
But consumers... I'm not so sure. I've seen a few people use BBs and they seemed amazingly obtuse. The only time I played with one for more than a few minutes I couldn't figure out how to do many (now seemingly) common things like uninstall an app or change it's position in the list.
The people I knew who liked BlackBerries swore by them for two reasons: they had a great keyboard and they did email.
But any phone manufacturer could make a phone with a fantastic keyboard if they really wanted to spend the money/time on it.
The email people all seemed to have started before the iPhone changed the direction of the market. When your options were a feature phone (terrible), a BlackBerry (built on email), or a Windows phone. BB was more popular than Windows Mobile, so it got the users.
The truth is, of the consumers I knew, email wasn't a big issue. The thing they all loved was using that keyboard for SMS, since most other people weren't using email on their phones either.
Basically, I think that BB's consumer market share was handed to them by default and momentum. People were drawn to it because as a smartphone they saw it as better than their dumb phone/feature phone.
On the other hand the iPhone had to convince people it was better than a feature phone, better than a BB, and (for many US customers) worth switching to a poor network.
I certainly agree that BB pigeonholed themselves and ignored the consumer market. With their momentum, they could have at least held a good chunk of the consumer market.
From my (admittedly anecdotal) experience, I'm not sure they ever earned any of their consumer market share.