[tanzam75]

Brand recognition is the one thing that might actually have been valuable. But then, it didn't save Blackberry. Which chose the option that you seem to suggest for Nokia -- of leveraging its existing installed base into a gradual transition. (Incidentally, RIM only sold smartphones, and had a peak market cap of $120 billion in 2007. Today, it's worth less than 1/3 of Nokia.)

Telco relationships and distribution channels are necessary but not sufficient. All the other phone makers had telco relationships and distribution channels, too. Didn't help them compete against the iPhone.

What got them some traction was that they threw out their old smartphones and started over -- 2 years before Nokia finally got around to doing it. That 2 years made all the difference.

There is an argument for Nokia ditching Symbian and keeping it secret. This assumes it could've been kept secret. A change of that magnitude was bound to leak out -- for example, a Symbian engineer quitting the company in disgust and telling the newspapers.

Disruptive innovation is called disruptive because it turns your assets into liabilities. For example, your factories and distribution network used to be valuable because they gave you scale that nobody else had. But now, they just cause you to have higher fixed costs than your competitors. The classic example being US Steel when the minimill disrupted the steel business.