True, though [anArray copy] is idiomatic in Objective-C too. It used to be that people would prefer arrayWithArray: because copy returns an owning reference and you'd need a matching release, but now with ARC that isn't really a going concern. I'd feel weird writing [NSArray arrayWithArray:anArray] these days.

I think the majority of Objective-C's verbose conventions are artifacts of the Frankenstein type system — for example, having two methods with the same selector but different signatures will cause any use of either method with an id type to emit warnings, and possibly to generate incorrect code if the types are not compatible. So in order to avoid these awkward situations, Objective-C prefers to be as explicit as possible about what it's getting and giving. (Case in point: The extra verbosity in the examples you gave is almost entirely caused by adding nouns.)