Dear friends, Please excuse my saying but this is the reason, one is encouraged to read the Help avaiable in the iMovie. Please click on the "?" icon on the main screen to completly understand the product, rather than just blaming and becoming upset.
Export to iTunes, is meant for 2 purposes.
a. To backup / archive your iMovie project on your desktop.
b. To edit the project in multiple devices. Lets say, you would use iPhone for shooting all day and then assemble the pieces on the iPhone and export it to iTunes and then import it back in to your iPad and then do more granular editing. It works like sweet. Nothing to complain about , if you understand the purpose behind it.
I fell in love with iMovie for iOS. This turns a iPhone into a powerhouse of video making. Can't beat this one..