Oh cool, now we know why it looks so stupid: it's because it's almost impossible to distinguish takeoff from landing if you don't exaggerate the angle.
Exactly, that's why I think this is a great pictogram: it makes it clear what it's supposed to represent, even though it has nothing to do with what a healthy landing looks like. A pictogram's job is to fit most people's conceptual model of what it represents while being simple and distinguishable, not to be an accurate representation of whatever it stands for.
This pictogram is simple (just a few shapes), it's easy to distinguish (e.g. from the pictogram for "departure"), and it fits most people's conceptual model of a landing (plane comes down from sky to earth).
