This is running a canti brake. It can have that safety concern if certain considerations aren't met. Careful setup mitigates much of that worry.
As it's set up right now, if the housing were to come free from it's stop, there isn't enough slack to drop the straddle onto the tire. The straddle cable can't come out of carrier pulley, it's closed. No more dangerous than any other brazed-pivot brake.
Nobody used a safety catch in the '90s before vbrakes came out. Only during the mid 80s mtb era.