Those can't go all the way down was restricted by door space. Some Mercedes even has weird glass movement (not just vertical up and down) to accommodate as much glass into door. This is another good thing about pilot's amply space.
Many years ago, car makers started making rear windows that didn't go all the way down because as the cars got smaller, they designed the back doors with a cut-out that went around the rear wheel. This limited space inside the door so that there wasn't room for the window to go all the way down. Many people wrongly assumed that this was a new safety feature to prevent kids from falling out of the windows. That was never the case, but I believe that many manufacturers (all of them?) allowed this myth to go un-refuted, turning a negative into a positive for them.
If you're worried about kids falling out, do two things - belt them in (as they should be anyway), and use the on/off switch on the driver's door to keep them from lowering the windows more than you'd like.