That is what it looks like will be very undesirable because it will be fragmented and competing with an all-world app store that is bundled with iOS. If you were a developer you would prefer 1000 sales at 30% cut, vs 5 sales with a 0% (supposedly still 30% if the chatter is right on Apple charging for sideloading) cut.
It would be struck down by the courts and version 2 of this regulation but for a few years it would be there.
I'm hoping apple doesn't do that but at this point I think they'll try anything they can to protect their golden goose (aka app store) even from minor competition.
The biggest problem with Apple's revenue model is that they want the 30% for people that aren't really benefiting from the App Store. Spotify built their brand without Apple, and if you want their app, you just click the link they email you.
You are speaking of licensing agreements to get access to the Apple SDKs, not to distribution. These are different things. Side loading on its own does not mean an end to contractual agreements to give Apple a revenue cut.
Isn't that what developers pay for to get access to?
(Distributing software is not always easy, as game companies that have 100GB game downloads on launch day will tell you. But, for most apps, it will be easy enough.)