Why? MBA take up similar room, and has full OS. Much better and more capable than a big iPad.
How do you use a MBA with one hand while walking about at an office, factory floor, medical ward or whatnot? Or perch it on a sheet music stand? Take pictures for reference or scan documents and whiteboards on the go?
Not everyone is using their iPads for Candy Crush and as a snack tray while slouching on the couch.