It is anticompetive, but it is apparently not prohibited anticompetitive conduct.
All of the major consoles since the NES (except for early revisions of the Genesis) have used technical means to restrict publication of games, and there has been no antitrust action on that. Nintendo was in a price fixing lawsuit and settled that with coupons for games with the Nintendo seal of quality.
If that's not subject to antitrust enforcement, why would the Apple app store criteria be?
Also, the US FTC threatened to investigate Apple over the "no third-party tools" thing they imposed on developers alongside "Thoughts on Flash". That's why they never followed through and removed it from their App Store guidelines.
So there is a limit - somewhere between "technical lockouts" and "we won't approve things made with third-party tools".
All of the major consoles since the NES (except for early revisions of the Genesis) have used technical means to restrict publication of games, and there has been no antitrust action on that. Nintendo was in a price fixing lawsuit and settled that with coupons for games with the Nintendo seal of quality.
If that's not subject to antitrust enforcement, why would the Apple app store criteria be?