A tablet is a specific one-task oriented device its not a full blown operating system. Try a Surface or a Windows 8 laptop/tablet hybrid and you will realize how overrated tablets are.
MS re-invented the phone making it more personal and puts a focus on communication and functionality. They made sure the WP is the best phone, camera, GPS, gaming, multimedia device all based on specifics not apps not features its about specifics and overall functionality. Even Android and iOS copied Social network integration with their latest versions of their OS. Phones are not PC's their used for communication not computing.
Living room. Kinect made TV interaction better. Smart Glass improves how you interact with the content. Xbox controller changed the way we play FPS on a console. Xbox Live changed the way we game online. Store allowed Indie devs to make money.
MS innovates they don't fukk around.