Epic wants to play the long game. They want the Epic Games store on PC and mobile and Apple is half of mobile. Having an opportunity to become the Steam of mobile is a very valuable proposition, especially given that IOS was apparently less than 10% of Fortnite income.
I see it as the opposeite of emotive; it's a cold calculation playing a very long game with hopes of market capture in a scene where no one else seems to care about premium games (including Epic. But who knows how that will turn out over the decade).