The buyer always wants the transaction to be more affordable and the seller always wants the transaction to be more profitable. The exact numbers don’t change that.
I think the thing that angers people is that the cost feels hidden, even if it’s common knowledge. You look at menu prices and see a price but tips, taxes, and credit card processing fees aren’t included. It can take you by surprise if you’re not thinking about it, even if you’ve been through the same dance many times before.
If I were running Apple, I would instead find a way to charge for developer accounts, code signing, etc. Things that are set up ahead of time and can have a known value, charged for upfront. I believe this would feel more fair, no matter the cost.
How much is it after a year?
Had they charged 10%, nobody will be complaining.