They may not be "hostile" but they are most certainly more likely to treat iOS as a second-class citizen or an afterthought, which is obviously not all that desirable. Depending on who you ask a half hearted port is worse than nothing at all.

By requiring a Mac to develop for iOS, they're forcing a certain level of investment which makes it more likely that developers targeting the platform make their apps worth the time spent (for both the dev and the consumer). By opening it up they're welcoming those who port just to tick a box.