deprecation, deprecation, deprecation - Part 1

The initial grievance for this posting is this warning:

foo.m:17: warning: 'NSLookupSymbolInImage' is deprecated 
(declared at /Developer/SDKs/MacOSX10.5.sdk/usr/include/mach-o/dyld.h:182)

When I look into the header I find this:

/*
 * The following dyld API's are deprecated as of Mac OS X 10.5.  They are either  
 * no longer necessary or are superceeded by dlopen and friends in <dlfcn.h>.
 * dlopen/dlsym/dlclose have been available since Mac OS X 10.3 and work with 
 * dylibs and bundles.  
 *
 *    NSAddImage                           -> dlopen
 *    NSLookupSymbolInImage                -> dlsym
 *    NSCreateObjectFileImageFromFile      -> dlopen
 *    NSDestroyObjectFileImage             -> dlclose
 *    NSLinkModule                         -> not needed when dlopen used
 *    NSUnLinkModule                       -> not needed when dlclose used
 *    NSLookupSymbolInModule               -> dlsym
 *    _dyld_image_containing_address       -> dladdr
 *    NSLinkEditError                      -> dlerror
 *
 */

and

extern NSSymbol NSLookupSymbolInModule(NSModule module, const char* symbolName)
AVAILABLE_MAC_OS_X_VERSION_10_1_AND_LATER_BUT_DEPRECATED_IN_MAC_OS_X_VERSION_10_5;

So it appeared in 10.1 and it's plug gets pulled in 10.5. Short lived API, I would say.

What bothers me, that one of the ideas behind Foundation is, that it should isolate me from the OS layer and abstract to a common denominator, that remains stable. Yet here, the Foundation functions are deprecated and I am suposed to use dyld directly, although Foundation still could (and probably does) do the work using dyld.

I don't get this.