There is a frontal shot I would take, but only in certain circumstances and only from ground level. Never from a treestand. The target area is pretty small, but I'm a good enough shot to make it.
The main reason such an emphasis has been put on the broadside orslight quartering awayshot is it's a lot bigger target area with easy access to the vitals. So thattruly is the only reasonable, ethical shot for the vast majority of bowhunters out there.
Not to mention the taxidermist will be cussing you no end for putting a hole in the front of the cape.