Android apps management architecture flaw?

I have just begun developing for Android and coming from iOS background. I'm really surprised to find out that a large number of Android phones including the Nexus One has so limited internal memory and it only takes about 5 apps to fill up that space despite having huge SD card memory.

From and end-user experience point of view, I couldn't understand why do I need to know how to move app to SD card and the worst part is that most of the apps that I need to use (map update, Facebook, Twitter, ...) can't be moved.

I couldn't shake the thought of a broken philosophy for user experience on Android.

I respect consumer choices but still... Can anyone enlightment me?