Tone and I were discussing just this subject over lunch yesterday.
We were talking about why some people love working in Objective-C and why others abhor it and came to the general conclusion that it is more of a philosophical issue than a technical one.
That the bits given to you by Cocoa provide the minimum functionality required while the frameworks of other environments try to cover every piece of functionality imaginable.
The former suits the makers and the latter, the assemblers.
I think there is room for both in this world (although I admit I belong to the first camp) but treating both types of "programmer" the same rubs both the wrong way.
This actually helps sum up why I like doing Flash work in Actionscript. AS3 has a single fairly narrow standard API with consistent structure and conventions. Flex has a much larger API, but still with consistent structure and conventions. When I stray from the comfort of my (admittedly user-unfriendly) marketing microsites toward the wooly harum-scarum of HTML/PHP/non-jQuery-Javascript, I feel slightly sick to my stomach.
On the other hand, Django/jQuery is pretty sweet. I think it's a matter of working with orthogonal and well-designed systems, more than the number of systems.
Yes, Cocoa is a massive library, but it has 99% of the things that I need. I think in objective-c and cocoa.
When it comes to web development I'm doing 100's of tiny little things in 2 different languages with 2 different markups to get something done.