Here's the bottom line for me, and only me.
I plunked down my money to buy what met my criteria for a practical, low cost sports car. To me, that means two things:
When I'm sitting behind the wheel with my foot to the floor, it looks like, feels like and acts like a sports car.
It also means when I stand outside the car, walking away and look back, I know I'm the proud owner of a sports car.
I've not driven a GTi in a long time, so I can't comment on whether or not it meets the first item as well as an FR-S. I can guarantee you though that on the second bullet the GTi (and any other econo-hatch cum race car) does not, can not and will not satisfy that requirement.
I will gladly concede 1 or 2 seconds on the track for bullet one to meet bullet two.