That's not right either, first off do you have all the market covered, secondly do you want to have all the market covered?
If most of the growth was in high glamour devices then NOKIA could not benefit from that growth as they had not produced such a device, just ugly, under-powered but functional ones.
The N8 was the first attractive smartphone NOKIA had produced in a long while but that was scuppered within weeks of being released by the 'burning platforms' fiasco.
If most of the growth was amongst extremely cheap low margin devices you might well make a concious decision not to compete but instead to cherry pick the market segments with more attractive returns, no point in being a busy fool.
The fact is NOKIA had growing sales and decent margins, now they have neither.