Haha I never really thought about it like that. I'm still going to stand by my tall cage thingy for multiple reasons.
1 hanging toys can be kinda long so it fits better in the tall cages.
2 they live in trees and enjoy climbing and jumping. Can't really climb if it's a short cage.
3 I'm not sure if this is all gliders but mine are happiest when they are farthest from the ground. They like my shoulder if they are on me. They like to chill in my bed (bunk bed by the celling) and if something scares them and they are in the cage they run to the highest corner and hide.
4 tall cages also tend to fit better in rooms. For example the Madagascar cage can fit through door ways while the double wide cage has more difficulty and takes up more floor space.
So yeah, tallness is where it's at. Of course if you can have a tall and wide cage that is far superior.