The height of prospective users is not the only thing that would be concerning. I'm still trying to figure out if that entire pack panel is removable for shipping.

Maybe it's hinged? Otherwise you'd be talking about a shipping box that is as big as a refrigerator. That would have added to freight expenses.

Also, when you think about the many times that we've moved a washer or dryer.... you have to handle the machine by lifting here, tipping it, grabbing the back splash, pushing it, etc.

Can you picture moving this gangly thing as is? Unless there is a SIGNIFICANT steel support system going all the way from the bottom of the machine to the top of the control panel.... HOW? Extremely awkward.

That's no doubt just one reason these interesting beasts were only made for a short time.

The 60s did have a number of "1964 World's Fair" type appliance innovations and designs.
GE had that weird laundry tub built into the top model.
They also had a skinny weird (but not tall) console for their washers/dryers for a time.
Maytag 900 All-push button models.
Microwaves
canister vacuums with powernozzles.
And it was in the mid 60s when built-in dishwashers started to become "standard" and not just a unique feature in new homes.

Another factor that probably factored into axing these- picture if you will, either of these machines operating, and vibrating under normal usage as they will.  There is always cabinet movement even if just slight on the dryer, but can you imagine that flimsy back panel jiggling during the spin cycle? They better have had lock washers on all the panel screws because even with a stiff support post on the corners, those panels must have looked unusual flopping around when the machine was operating.