Huh? You know how long it'd take to open an excel spreadsheet on the iPad, modify 10-15 cells, save it, then attach it to an email and reply with a paragraph of text? About 20x longer than if you had a keyboard\track pad and full version of Excel.... to those who are saying it's just a glorified iPad I'm really in awe that you think this way. iOS vs Mac OS is like a bicycle vs a car.
Even a simple copy/paste is a lot more time consuming on an iPad than on a Mac, and I don't necessarily get the text selection right the first time.