There is a continuous scale between this kind of attack and the kind of "nigiri-ho" kokyu technique demonstrated by Shioda and Saito Senseis, among others, where the grip specifically enables you to control your partner's centre directly. It can be an immobilisation - just as the ikkyo pin is - but it can also feel like an electric shock to you as uke as your strength is mysteriously taken away.
So, George, I agree with you (I think).
Look, if you have the equipment, i.e. large hands, monster forearms, and enough mass to deliver the "grip of death", then great. But it's not only a useless skill for smaller people, male or female, but training that way is counter productive if you will never have the kind of strength where it was any function.
I don't want to get into one of those "style" discussions... but some approaches are only suitable for very strong people.
Most students are, well, average
. And if you are average you are not immobilizing anyone with a grab. Not happening, silly to try.