As a developer I can say with certainty this is not the case at all. Microsoft has provided the best development tools, frameworks, and APIs for years. This is actually one of the main reasons MS was so successful in the desktop/server market. They made it relatively easy for third party developers to create useful programs. The WP platform is no exception.
The reason that WP is lacking in third party apps is because the WP OS was late to the party. It's a chicken and egg situation. Developers don't focus on apps for WP because it doesn't have a lot of market share. WP doesn't have a lot of market share because it doesn't have apps from developers. This isn't an impossible situation to overcome, but it does take time. At some point, as long as the platform continues to gain market share, it will reach a critical mass and apps will start showing up fast.
Exactly my thoughts. WP fails to reach the level it deserves because developers want to develop for an OS with at least 10-15% marketshare, and that marketshare wont grow till developers flock to the OS and make quality apps for it.
MS is in a fix and this is all because they dint start early on. Immediately after the iPhone was revealed in 07 MS should've started giving a lot of attention and buliding the WP8 we have now. Even if WP8 would've arrived in 09 in the form we're experiencing now and with nice team up with Nokia and HTC, today WP8 would have atleast a 30% market share. They arrived late, quite late.
Now according to me, the only way MS can ever reach the 15-20% marketshare would be to continue building and strengthening relationship's with handset manufacturers especially Nokia and HTC as both make very neat phones, and at the same time it needs to improve the OS and get all the functionality that iOS and android have, even if it's in a different 'style'.
And most importantly, MS should give a LOT of attention to its store, and attract developer's. The giant that MS is, i think they should just start a totally new department that ONLY makes apps for Windows8 and WP8. Possibly even buy out a few mid-size developers, not the size of Rovio or Zynga, but even a couple of mid-size developers who have been known to make solid useful and fun apps for any ecosystem. Once this department builds some solid amazing app's, which could even possibly be WP8 'exclusives', more customers and developers in turn will be attracted towards the platform. And skype integration would be a very nice thing to have as well.