It all sounds pretty reasonable until you remember that the 30% tax is more or less aimed directly at removing Amazon ebooks from the platform, and that the kindle app was available well before iBooks.
Lots of books apps were available before iBooks. Apple has no interest of driving any content provider off iOS: anything that helps sell hardware is good for them.
And Kindle App is still available on iOS.
Once June 30 goes past, Apple isn't going to reverse their policy again; if Amazon is there on the 30th, they're not leaving.
No, Amazon leaving now would make it look like Amazon pulled the app. Perception is very important. Most of the customers do not read tech sites, but they will notice when apps are pulled, and will ask 'Who pulled my app?'? Amazon (and I suspect Apple as well) wouldn't want to be the answer to that and be object of rage.
If Amazon doesn't want to play by the new rules, I suspect they will wait for Apple to make the first move.
This is definitely true of Netflix too, I suspect there's a percentage of iPad buyers who bought the device just for Kindle/Netflix apps.
It wasn't the only reason I bought an iPad, but had the Kindle app not been there, it would have certainly been a deal-breaker. And even if they back off now, the uncertainty Apple has introduced has driven me to an Android replacement. I simply don't trust Apple to proceed with the customer's best interests in mind anymore.
Make a beautiful logo out of it, constantly reminding people that the price increase is due to Apple.
... and at the same time offer a clue that they can get the same services/goods cheaper on another platform (say... Android).
Would that help to drive users to understand how bad Apple is and hopefully start a public uproar?
Perception right?
No one except very small companies are going to go this route, if any.