Why does dropped toast so often land butter-side down?

Dropped toast seems to land butter-side down, and studies found it usually does.

As toast slides off, its front edge drops first, so it tilts and starts to spin. The longer it falls, the further it turns. A table two to six feet tall gives it time for only about half a turn.

So the butter, which started on top, ends up underneath. Only a table over 10 feet tall allows a full turn.