#2 The New Ribbon Desktop Interface Is Different, But Functions In Same Way:

If you like that aero look of Windows 7, than Microsoft decided that this is not a worthy feature for Windows 8, and had apparently removed all transparency effects from the desktop interface. The change however suits best for hand held devices like Windows mobile, or tablets, the same cannot be said for desktops. Overall, only look changed, but the new look does old stuff yet.      

#1 Windows 8 Comes With “Learn Before Operate” Tag:

The new OS delivers what it promised—a new experience. In other words it as high learning curve for its new UI, performing a simple operation like shutting down the computer for some reason teases your brain.  And then there is added confusion about separate interface; pressing a button switches from desktop to Windows 8 UI and vice-versa, which may put the inexperienced users in spot, who used single interface to conduct all operations.