Most of the "flintlocks are less safe" nonsense is probably "knowledge", camp fire lore and old wives tales that have been passed down for years.....probably going back to the basic idea that the Scout instructors didn't want to mess with priming pans, knapping flints, finicky guns etc. So they just said "cap locks only for "safety" reasons" and that was that.
Plus its much harder to use powder subs, in the event someone has to stop by Wally World and pick up some Pyrodex for a Scout shoot... because anymore one gun shop in a 200 mile radius even sells real BP.
I can honestly see why they just want cap locks. Being someone who has been a range safety , has instructed people etc , the name of the game is KISS.