While most people do install apps through the Play Store, Google doesn't lock down their platform to make it the only option. I have one alternative store (F-Droid) installed, and also have a couple apps side-loaded.
Google's 30% isn't the only option on Android. Apple's 30% is the only option on iOS.
Regardless, Google gets plenty of flak here for a variety of things, including how they run the Play Store.
Developer fee for the Play Store yes, but no developer fee for using the open stores (although I'm well aware that in certain environments it is disallowed to use other than the Play Store) or developing local apps.
I really don’t think it’s about side-loading, principles of freedom, the spirit of hacking, etc. HN’s full of indie app developers trying to make money. They know iOS users more often pay for things so it’s their target audience.
I doubt existence of F-Droid is even a drop in the bucket of fee savings for those developers on Android. Otherwise, Google would do something about it to get their cut.
Google's 30% isn't the only option on Android. Apple's 30% is the only option on iOS.
Regardless, Google gets plenty of flak here for a variety of things, including how they run the Play Store.