I don't think the 4 door is a particularly bad looking car by any means, but I find the 2 door to be much better looking. Yes, it's the same roof line and body shape, but the less interrupted lines, particularly the glass, creates the illusion of a longer, lower shape.
As far as practicality goes, I've never understood people who like to put things in the back seat area. There's a giant door at the very back which opens to a much larger area to hold things that doesn't have a sofa bolted to the floor in the way. The reality is I still would have bought a 2-door GTI even if the back seats were much smaller and less usable for a full-size human. You can think of it like there are extra seats back there that are walled off in sheet metal, but I prefer to look at it as there are mostly useless (to me) seats back there that have the bonus of actually fitting a person if ever needed.
If I had kids, I'd go for the 4-door. As it stands, I carry more than one other person on very rare occasion, always adults, and it's never a problem. My back seat might get used a handful of times a year - not nearly enough justification to get a car I don't like to look at as much.
If I had gotten my car later and couldn't get a 2-door, I'm sure I'd have gone with a 4-door instead of going to another brand or model. As it was, 2-doors were always harder to come by, and for 2016 they were order-only, so I ordered and waited for 3 months for one exactly as I wanted it.
I've owned 10 cars, only 3 have had more than 2 doors. 1 was only available that way (Mazdspeed3), 1 was something I needed to buy quick and cheap (Dodge Stratus, but at least it was a stick), and the last was a second winter beater that was difficult to find rust-free, let alone as a 2-door (Jeep Cherokee XJ).
I'm willing to bet that the GTI has the best, biggest back seats out of any car I've owned, 2 or 4 door.
Completely self-serving pic of my car: