Full length IPad 2 movie

Something that i learned from this article is that  A full length movie was filmed entirely on an iPad 2. Another thing I learned is that the creator of the film actually wrote the script to be filmed on a iPad 2 specifically. I also learned that the film was edited in final cut pro. A thing I like about this article is that it shows how a full length feature film can be made with a exceptionally low budget. I also like that it showed pictures of them filming the movie. A question i have about the article is why an iPad, like why not just use a cheap camcorder?