Poles?
1/I have been hit by poles, but luckily not in the face, though it has been close. Whether carried by the handles, halfway along the shafts, or attached vertically to a back pack, their owners often seem unaware of where the points are, putting other people at risk.
2/Are poles an aid to balance and therefore safety? I think they subtract from the normal rhythm of walking, and act like the opposite of balance training - and you see people doing all sorts of silly manoeuvres with poles when they should be using their hands, not the pole ends.
3/They are just another bit of kit, and are prominently advertised in the trail walking magazines - and of course people like kit, so they buy them.
I can see that they might have a role to play in long events to help preserve leg strength, but most who use them are not doing anything remotely long.
So I was pleased to read that ba-ba had not used them!