My point is that regs and AIM you do not tell you which Tower position to call. And I don't know of a towered facility anywhere that has an ATIS broadcast telling a pilot to call the Ground position for taxi instructions.
Special local procedures do typically get placed on the ATIS. But common procedures do not, even if they are not mentioned in the AIM or FARs.
Like what we are discussing in the thread. So far anyway, I have not been to a Class D which said "Contact ground before taxi" in an ATIS broadcast. Nor would I want it to. For a Charlie, I have not heard one say to contact CD or Ground. Those contacts are something we are taught to do because it's he way it's typically done.
Calling CD or Ground? I'm more interested in reality that myth busting. Hopefully, we're savvy enough not to call the Tower. But we're sitting n the ground, so it really doesn't matter. What's the worst case scenario if I call "the wrong" one? The position tells me to call the other and I've learned something for next time.
So, you can tell new pilots to just call the Tower and forget about Ground or CD. I'll continue to teach that certain procedures are common, but not all facilities are exactly the same. Pay attention to NOTAMs and ATIS for special procedures but understand that not every minor variation will me mentioned there and that it's no big deal to be wrong about those.