Nokia along other big companies has tried a bunch of different strategies on it's way including touch, services, Maemo, Meego and QT. Seems that big organizations can only handle one -ism or vision at the time. The need to renew strategies completely can lead in ditching all parallel scenarios while striving for optimal beauty of a chart or simplicity of communication.
So why do these visions and strategies change so fast?
Creating a vision is a crucial competence for a leader. When things go wrong (stress rises narrowing the line of sight and lowering the willingness to discuss) the urge to form a strong vision can become the last straw to keep up the reputation, although the vision might be personally driven or not just good. When the vision is set, leader’s competence is measured in how well the strategy is implemented - no matter what it is.
Adapting to new situations is crucial, but evaluating when a strategy is based on actual situation and when on personal drivers can be difficult. Stupidity should be easy to detect, but we want to believe in people and their decisions - to trust that there is a good reason behind every decision.