That's irrelevant. How is rapid growth and significant marketshare 'irrelevant'? Even if other vendors put Windows Phone on the back burner, Nokia phones are

That's irrelevant. How is rapid growth and significant marketshare 'irrelevant'? Even if other vendors put Windows Phone on the back burner, Nokia phones are the most popular by far (according to most surveys 80% of the Windows Phones sold are Nokia phones). If they continue Nokia's tradition of good hardware at low prices, that can drive sales, while the ecosystem grows. Also, it's not as if HTC is making big profits with Android. They'll probably want to spread their bets.