Microsoft surely knows.
As most tech geeks know, the Windows Phone app count after 2+ years is still very small (that is pretty much an understatement).
There are many gaping holes on the Windows Phone store that prevent people from switching over to the platform, like Instagram, bank apps, productivity apps, to games that are only popular for a few months (Like draw something). Microsoft and Nokia have been pursuing app developers for a very long time, with Nokia having modest success.
Microsoft has failed in getting app developers on board. Now, a petition has been started. It is not aimed at developers themselves. Rather it's targeted at the company that should be trying to get as many apps as possible. Microsoft. Users shouldn't just hop that they get apps...
You may sign the petition here.
This isn't just about getting apps like instagram and temple run, but also about engaging young app developers in markets with high windows phone penetration.