The axe hammer combo was new to me. I got axes, I got hammers - but somehow the combo of having an axe pointing towards me when hammering just seems like a accident waiting to happen? Might be just me.
Respectfully, though, I think this concern is largely unfounded. When using other types of hammers (claw, ball peen, sledge, etc.) how often/how many times have you managed to hit yourself with the back side of the hammer? Come close to hitting yourself with the back side of the hammer? I'm guessing the answer is probably never/none.
You can always leave the cover over the blade while using the hammer.