Yep that's exactly the reason, plus not wanting to compete with Pixel Dungeon. The developer talked about it when first announcing it was coming to iOS
> Shattered Pixel Dungeon will cost $5 US when it fully releases on the App Store. I’m charging because of a mix of Apple’s higher platform fees, not wanting to undercut Pixel Dungeon, and because Shattered is releasing in a much more finished state.
> Shattered Pixel Dungeon will cost $5 US when it fully releases on the App Store. I’m charging because of a mix of Apple’s higher platform fees, not wanting to undercut Pixel Dungeon, and because Shattered is releasing in a much more finished state.
https://shatteredpixel.com/blog/shattered-pixel-dungeon-is-c...