Why does only Facebook gets this special king size treatment on WP8?

So, I have started to use my WP a lot these days and I see Facebook being integrated everywhere into the operating system. Literally to Every nook and corner of Operating system.

Starting with lock screen, People hub, Calender, Photos, messaging, photos, Camera everywhere. My Question is Why is this special treatment provided only to Facebook.

Its right in a way to think that Microsoft sees Facebook as the only possible way to take on Google's empire, but in my view it should open up all these features to every other app as well.

It would be really nice to have Skype, GChat, Watsapp all inside the messaging hub which currently supports only Facebook.

It would be really nice to have Picasa, Flickr, Dropbox all being integrated into Photos hub just like the way it happens with Facebook and Skydrive.

Those are 2 major things I think of.

I would like to know why isn't this possible?