Edit again (It's Magic Hat's fault today): Consider how much of a grab you really need, even in katate-tori. Squeezing the wrist isn't the point. Connection to center is the point.
Oh, I absolutely agree.
But it sure as heck *looks* like a grab to an outside observer, and it will still be difficult to accomplish for someone with dysfunctional hands. And the same for aikido's other hand manipulations.