Does anyone notice this on Windows Phone? Is there a technical reason behind this?

You know I've been using these apps on Windows Phone 8 like Skype, Facebook etc. Saw the walk through video of 6tagram and used Instance as well. It just doesn't feel right. There's something in all of these apps that makes it feel like I'm using a web app or something. It's just not as 'seamless and smooth' as iOS. Everything from clicking a button to the time it takes for it to respond or for a new page to appear.

A simple example of what I mean is, take the stock apps for example. When you click anything, like a name of a person in the contact hub, the swoosh animation that occurs or how seamlessly it transitions from one menu to another. Or just look at how stock apps like messages auto-rotate, notice the rotation animation, it's nice and smooth. There is NONE OF THIS in ANY third party app. Moving from a stock app to a third party app on Windows Phone, there is a massive change in overall feel and performance.

And please, this is in no way an attempt at trolling or anything. I genuinely like this platform and this is something I'm very interested in knowing about. Is there a technical reason behind this? Is it because of the coding language or the SDK for Windows Phone? If someone notices the same thing, please shed some light.