I think the real "ipad isn't a real computer" thing is that you can do arbitrary stuff with the computer. I can have arbitrary programs open. I can write arbitrary programs. I can arrange them arbitrarily. I can open dozens of them and keep them open in memory. I can push my device to the limits of its resources if I want and it won't try and offload anything stupidly on me, it will do what I ask of it.

But you could always make an app to handle car rentals for ipad or iphone or whatever. You could make an app for lawyers doing documents. That was never the argument against "ipad isn't a computer." It doesn't expose the file system to you. More than anything, it tries to keep up the curtain between you, Dorothy, and the wizard, who is just a man after all. That is why it is not a real computer and will never be one fundamentally.