Why compare to Square's or Stripe's fee structure? It's ridiculous to claim "This means Apple's taking for themselves much closer to a 5% cut" as if Apple is paying a $0.29 processing fee per IAP.

If developers had a choice in payment processors, they could choose one with smaller minimum per-transaction fees, aggregate multiple payments from the same customer, try out subscriptions instead of microtransactions so the payment processor takes a smaller cut, etc...