I don't get why a GL would choose to be in the League. Their primary responsibility is their space sector and they already belong to a large scale group with the GL Corps. In fact, there's times the Leagues agenda may conflict with that of the GL Corps.
Same with Batman. He's more concerned with the going ons within Gotham City, IMO, than with the rest of the world. Unless his reasons of being with the JLA is to keep an eye on them.
