The "press or say 1" construct for IVR menus was rolled out by AT&T about 15 years ago, when speech recognition was new. There was a "wow" factor at the time, but those days are long gone. Still, I work with companies that feel a need to use this in their own IVRs and I can't understand why. When I ask why this is needed usually the response is "someone else decided this, we're not sure who, we just do project work." So someone high up in the food chain made the decision and we, the lowly consulting company, can't talk to them and try to get the decision changed.
There's no IVR design guild but if there were one it would dedicate itself to iradicating this practice.