I don't mind if people want to pay for someone to curate their apps, but I don't see any reason developers shouldn't be able to charge those people +43% for buying through the curated app store. If there's really as much value as everyone claims then users won't have a problem paying extra, right?

I also think it's crazy that IAPs are viewed as anything more than a simple payment that would incur normal payment processing fees. You'd never find anyone willing to argue that VISA or Mastercard should be able to charge 30% for payment processing because of the infrastructure they provide for merchants.

Framing the 30% as "payment processing" is a fundamentally flawed comparison. Apple builds the entire ecosystem and suite of tools that developers use to actually make apps for the iPhone.

Visa and Mastercard only provide payment processing, they don't provide the equivalent of the iOS SDKs, Xcode, the App Store, etc., to their merchants.

I think there's some value in that tooling for building the apps, but for IAPs Apple's not doing anything more than payment processing. There's nothing special or difficult about processing an IAP and there would be a line of competitors around the block to do it for <5% if they were allowed to.