Don’t Create Umbrella Frameworks

Hi,

I have question on one statement in Framework Programming Guide. In the programming guide, it states "Don’t Create Umbrella Frameworks" as best practice and it doessn't state the reason why we shouldn't do that. Can I get some explanation? I am a SDK developer and other developers includes my frameowrk within their application. General speaking it's good idea to mask our internal dependencies and internal frameworks, and expose only public interface to other developers. Is there a reason Apple suggest not to go with this approach?