I hate to tell you this, but the iPad is pretty popular with writers. Set it in portrait and pair it with a keyboard, and it's a perfect little document machine.
The iPad isn't popular because it appeals only to the lowest common denominator. It's popular because it can do a little bit of everything in a very portable package, and it's only going to get better at doing a little bit of everything as time goes on. Eventually, it's going to come a point when tablets are going head to head with laptops.
This is fact as I see it daily. Honestly for now the iPad just works.