That works very well for services where the app is not the main product... Like Hey.com. They do their own market and don't need the "visibility" of the app store.

They would be pretty happy if they could have a link on their site to download the iOS apps, for their customers.

If Apple still wants to review every app that can be installed, they could propose an option to be in the App Store but unlisted - then the fees goes down to 2 or 3%, just like a credit card fee. But they won't, because they can get away with shaking businesses 30% so they'll keep doing it until someone forces them to stop.