I'm an active blender's user. And i find the interface very productive too..like any other "real" blender user.
However, we are in a big world and , yes, THERE IS other 3D apps over there..
People spent a lot of time learning these apps, and these apps tried to UNIFY their UI. Actually,If you do ctrl+c it does copy something . When you alt+mouse , the 3D view does something.. Well, not in blender. And that's the problem, and that's why the next version is all about the new CUSTOMISABLE UI :)
Take care of blender.. it's one of the best real open source projects actually.
congrats tom, you're a big guy !