Why Obedience To Other Than Allah Not Regarded As Shirk?
Just the way doing parastish of anyone other than Allah is regarded as Shirk, simialrly obedience to anyone other Allah will also fall under shirk, when done for someone as rival to God or parallel to God. Parastish, in all its exhaustive forms, is done for God or for someone parallel to God in the same capacity; obedience however has variations in both its intensity and its physical manifestation and it varies largely with respect to the person for whom it is being done. The obedience to wife and/or superior in an office are the kind of obedience which arise because of certain familial or legal relationships and are in no way the same kind of obedience which is required for God in his capacity as God. The day this happens, it will definitely be categorized as Shirk.