...then don't buy from apple.
This isn't overly complicated....
If you don't like the payment structure then don't post your app on Apple's webstite. If there is no content for the iPad then no one will buy iPads. See how this works?
But no....the American way is to bitch and whine and then do what you are told.
I, for one, would jump to Android in a heart beat if Barnes and Noble or other content providers said, "enough!"
Also, if they pass the cost onto consumers buy increasing content cost I will switch.
Righting a sternly worded letter will have NO impact at all. Apple will hardly blink at being called a doo-doo head as long as developers continue to put apps on the site and people continue to buy them.
I beleive the old saying is: Talk is cheap...