Thanks to Gruber for pointing out this gem from April 2011:

Importantly, it's not a question of which platform [Android or iPhone] is "better." (This is irrelevant.) It's a question of which platform everyone else uses. And increasingly, in the smartphone market, barring a radical change in trend, that's Android.

So that's why Android's gains matter. And, yes, Apple fans should be scared to death about them.

Fast forward 3.5 years to today. Re/code:

While Android continued to gain market share in the global smartphone market, it saw a significant drop on another key metric: Profits.

Analyst Chetan Sharma estimates that global profits in the Android hardware market for 2014 were down by half from the prior year — the first year that there has been any significant drop.

And then Sharma nails it home:

“It is important for Google that the ecosystem stays healthy and balanced. Without profitability, some of these players will eventually disappear and it will primarily become a Samsung + Chinese OEMs ecosystem, which is probably not what Google wants.”

Moral of the story: market share is a superficial number that doesn't tell the whole story. What's the point of gaining market share if it doesn't help your business sustain itself?