Interestingly enough, the author of the article complains about the fact that larger people would not fit. It's not the car's fault.
The other weird comment in the article is about the radio volume placement which, by design, is placed on the center console not the floor console and the "issue" is that's on the driver side rather passenger side and supposedly the passenger has to reach for it. I can't think of any car that has the radio power/volume button on the passenger side. Particularly in Golf's case, the car is small enough that the knob is close to the passenger anyway. Pointless remark IMO.
You're right that the seats are not the car's fault, but it's the car manufacturer's fault when the only seats available are not suited to a variety of body types. Like I say in the review, I'm skinny so I fit fine, and I loved how supportive the front seats are. My wife is not skinny, and she hated this car as a result. However, she would have liked it fine if, say, the seats in my test car were an option. Why should only small people be comfortable in small cars?
As for volume controls accessible to a front passenger, Audi and Mazda put the volume control on the console. It's a good design. I wish it were more common.
Also, having literally just tested this car, I will respectfully disagree with you that the GTI's volume knob is close to the passenger. If you're tall and adjust the passenger seat far enough back to accommodate long legs, it's a long reach to the left side of the centre stack.
