The reasonning looks good except that, why are so many different vendors able to sell real cheap netbooks then ? Make the screen sensitive, remove the keyboard and this cheap netbook become a 300/400$ tablet. Also about direct selling, that has been Dell’s position forever. It works well for them, but *not* to the point of giving them enough of an advantage to get rid of all competition.

I believe the answer might be instead that Apple has secured the majority of the world supply of 10″ sensitive screen, and that the manufacturers knowing there’s only a very limited supply of them available will sell them to other companies only at a high premium. This means it’s very hard for those vendors to compete on price, so they focus instead on providing much more features than Apple which makes them even more expensive.
If this is so, this means manufacturers of 10″ sensitive screen are currently making a huge profit, so every electronic firm will try to get on that market and produce more, which means it won’t stay so very long, and we’ll see cheap tablets once the undersupply of 10″ screen ends.