I don't understand. How does buying an iPad prevent people from using other computers for those purposes, or wanting to, aside from the opportunity cost of actually buying the device?
You seem to be talking about things that machines can do, but you're referring to people. If a machine is limited it does not follow to say that the person is limited.
Of course the person is limited. They are limited because they can't for example, install Firefox on the iPad and use it as the browser rather than Safari. The person is limited because the locked nature of the device limits them.
