Associate
Tomi's own data:
OS market share by quarter
Symbian; Q1 2010, 50% - Q2, 44% - Q3, 36% - Q4, 32%
Android; Q1, 9% - Q2, 18% - Q3, 25% - Q4, 30%
You seem to have confused yourself by not looking at that graph properly. It is comparing sales of the three largest smartphone hardware manufacturers. Not the three largest operating systems. In other words both that graph and the figures you listed are true.
Nokia/Symbian was losing market share because it was growing slower than the industry as a whole. But still growing. Yet at the same time no individual manufacturer was coming close to Nokia. Nokia was still the biggest and would be for some time. Nokia needed to get their act together but it certainly didn't need a dump-everything-and-get-into-bed-with-Microsoft approach.
The rest of your arguments seem to ignore that while the industry was growing massively it's because of a lot of bit-players in the Android market. Android was becoming big but (as I just said) there wasn't anyone even coming close to Noka. It's like saying Macs are a niche player in the PC industry (which they are if you look at operating systems). But then when you look closer they are something like the second biggest PC manufactuer. That is what Nokia destroyed (except they were the biggest).