What is worrying, is, that if somebody nicks your credit card info, scam you, …, using alternative payment, people will, most likely, blame Apple for everything. It might create a damage to customers, to brand and to an overall image
I know App Store is not perfect, but we chose it over Android, and Microsoft mobile, for a reason. If you do not like it, you can always switch. You will have more options, cheaper devices. As for developers, 15% or 30% percent, is a bargain. The pre App Store hustle, developers were lucky to get probably 30 to their pockets, not 70. People will moan and want more for less.