I continue to be amazed how so many people think that because an iPad doesn't meet their needs for a computing device, then it can't possibly meet the computing needs of many of Apple's customer base. That's very narcissistic.
Not everyone in Apple's extremely broad customer base needs to run Photoshop, MATLAB, FCP-X, Maschine, Autocad, Mathematica, Maya, Lightroom, etc, etc.
Rather, Apple's customer base is very diverse. Many just need a device that can be used to send and receive email, surf the web, manage an appointment calendar with reminders, write some letters/notes, read a book, watch an occasional movie, edit and manage some photos, put together a home budget spreadsheet, edit a home movie with iMovie, plan a trip, listen to music, manage a contacts address book, read some pdf documents, listen to a podcast, send and receive some messages, play some games, watch the news, do some calculations, check the weather, engage their home automation setup, make some sketches, and on and on and on.
And for those many many Apple customers...an iPad meets their needs, is easy to engage and use, is relatively compact, and is an ideal computer.