It's a little baffling how he thinks that Apple might charge up to 10% to handle payments when they already charge 30% for handling payments.
See: Amazon's Kindle app for the exception that proves the rule. Amazon has their own Kindle marketplace where they take a significant cut, they where willing to give Apple a slice of the pie just not 30%. So they ended up removing in App purchases from their iOS kindle reader. The back door is you can still use their website from your phone and order a book through them which will show up on all your Kindle readers.
However, random App makers don't have the customer leverage to do the same thing.
Follow up question... how many app developers would suddenly be profitable if Apple only took 3% (or even 10) instead of 30%?
But if not 10% let's just say 2%... it's still an AMAZING business.