Earlier quoted context omitted.
The difference is that the hypothetical third party Android App Store could use any payment service it wanted, or even the user could use any App Store it preferred. With iOS not only you can't buy from a third party, you can't even install an app that hasn't been signed by Apple.
I would argue the point of consumer choice is at device selection. If they choose the ecosystem with the heavy markup, when they had alternatives, then they are responsible for incurring their own additional costs. The information is public regarding app costs between devices and marketplaces. This seems to me a bad ruling based on that.
Either way, end users have the right to sue Apple here, not just the developers.