[orev]

The half pane of glass is appropriate in warm parts of the world where you want the heat to be removed as quickly as possible. I suspect some hotel executive thought it looked cool in Miami, then made it the standard for the whole chain.

[Arainach]

It's not even appropriate there. Ventilation should be determined by the fan, not the aperture.

Even in Miami, I don't want the entire bathroom floor flooded, and I want to be able to close the curtain/door and increase the humidity in the shower.