Well, not really, as I already understood all that.
What Spice is asking for is really a zero-voltage reference, not a ground. However, I'm sure it's called "ground" for historical reasons, and since nobody else seems to have a problem with it, I guess there's little point in speculating why.
If it were me designing the software, I'd just ask for a zero-voltage reference point, with "ground" as an option for those circuits that really do need a ground (audio amps, RF circuits, etc.).