Designers design for usability. The idea that design is about "making things pretty" is on par with the idea that software development is about making computers crunch numbers.
Not sure how that has anything to do with the parent's argument.
It wasn't usable for the majority of the market. Even in the infamous mea culpa Apple made about it, they admitted they designed themselves into a corner. It was designed so poorly, they had to take years to undo it after admitting it needed to be done.
GP was complaining about the common and incorrect trope that design is limited to aesthetics.
In theory.
In practice, designers design for two things: market demand, and personal predilection.