How is that different than web developers being required to dance to the tune of basically every major browser? They all have little oddities that have to be taken into account, speaking as someone who has done quite a bit of web development, every major browser has it's deviations from the standard, intentional and often otherwise, that require little tweaks to one's code.

And to be totally honest with you, a lot of Safari iOS's quirks are unambiguously good, pro-privacy practices that frustrate the shit out of surveillance marketing firms and I quite hope Apple keeps it up.