Is it? There seem to be a hundred million Java developers out there, that can do an Android app, plus even release that in-house or with minimal registration fees if single dev/sideproject.
For Objective-C/Swift, there seem to be ten percent as many devs.
I always only tinkered with Android apps in my spare time, but never managed to deploy anything to iOS.
Also, outside the US, iPhones are a 10 % niche product in private hands, but companies might use a lot of iPads or provide iPhones as work phones, so perhaps companies do think of both platforms as second class citizens (behind windows/browser as two other "OS-like" primary platforms)