Just because I'm somewhat devious.... with your example it's not obliged to move over 6 pit squares .. only 4 are enough, by going diagonaly up then down or down then up ! ;-P
OK, if you put walls in place of empty spaces on your first and last row there it has no choice but "flying" over the big pit of 6 quares long !! ;-)
But I understand what you mean, and I also think that's not really logical..
but with such games I have learn to put logic aside because the rules are here for balance and not for really, even If I think the conceptors try thier best to stay as logical as possible.. they don't always succeed !