Since Android is Open Source, Google cannot dictate manufacturers to use a certain quality or type of hardware to maintain a uniform quality experience. Also, Android's Java Virtual Machine DalvikVM sucks... too resource intensive, but allows Android to be Platform Neutral...
But Microsoft can dictate specifications of mobile phones in detail if manufacturers want to use WP7. That is why Samsung had to use Qualcomm chips in its WP7 phones instead of its own superior chips...
Because of this standardization, quality is maintained. It is just like the iPhone, but with multiple manufacturers... Essentially a hybrid model between Android and Apple...
Android experience can never be perfect for these reasons... especially on cheap sub-15k devices... iPhone 4 costs 35k+... how can an Optimus One compete with it, when we know all the limitations of Open Source Software?
It has nothing to do with Open source vs closed source.
WP API is way too much restricted. its Architecture is a total copy of iOS. This is why it does not match with iOS or Android.
MS has never forced anything to OEM except the minimum specs.
All WP phones look same on UI front. this makes me wonder how Nokia or other OEMS's is going to differentiate their phones with other OEM's
WP , just like iOS is not doing true multitasking. As per WP architecture, only 1 app can be in foreground (obvious) and all others (max 4) in background.when a app goes in background, no code can run and app freezes. it cant use any phone resource except RAM. If u open a 6th new app, out of 5 app in memory , 1 will be killed.
this way , WP is similar to iOS and hence not a true multitasking platform.
API is very much restricted. eg. i cant problematically add a event to calender.
If there is any chance for WP to catch up to Android or iOS , they need to have FAST release cycles..else its just gonna play a catch-up game.