The Devs said that, it would cause clipping on the gear for those with hoods down already. The /hood wouldn't work because you have a head piece and would have a hood, with your head piece clipping through the hood.

As for cowls (hoods already raised up) they said they could do this with the darklight, but they would have to redesign the gear as two separate pieces so it would read it every time you did /hood, and they feel time/resources would be better spent on just designing complete new gear sets for us instead.