The thing about hatchbacks is that there is a fundamental simplicity to their shape. Cutting out the trunk leaves them with a clean, unified form.
Take, for instance, this Honda Civic hatchback. It's what you would call a 'two box' design. There's one 'box' (in yellow) for the front of the car, low under the hood, where all the engine and drivetrain goes. There's a second 'box' (in blue) for the rest of the car, with room for all the occupants. If this car had a traditional trunk, that would jut out and make it a 'three box' design.
This particular third-gen Civic looks amazingly clean and simple today. It was very much a product of the '80s, so the lines and straight and the panels are largely flat. Back in the day it might've been a little boring or conservative. Today it looks remarkably restrained and sharp.
That is, if you can find one today. It feels like most of these things either rusted off the road, or failed emissions testing ages ago with an arcane vacuum-line brainfuck of contemporary compliance equipment.
What hatchback design do you think is even simpler, classier, cleaner than this '80s Civic?
Photo Credit: Honda