in years to come, this will be a great case in poor management!

Nokia's sales are crippled because of Symbian. Every review of symbian indicates that it lacks apps, are too slow, and no bling-bling UI which is what everbody (apperently) want.

However the strategy is too keep feeding the smart phone market world wide with symbian units (that doesnt sell) in years to come. From 2009 to start of 2012 symbian is the only thing Nokia can rely on and especially in 2010 and onwards Nokia sales drastically decreased because of Apple and Android.
Summer 2011 Nokia had an option to release a Product, N9 which in reveiws had very differently popularity among test-sites than Symbian ever had.
That product, however, were only released in few countries and therefore only had little impact on the net income. The bottomline were that Nokia had little to no revenue from Q1 2011 (after the release of N8) to Q1 2012(the first Nokia mango mobile).

What went wrong? Was it the classic "group think" were directors and board members thought they could walk on water?