why do dragons breath fire, why not lazers?
I think this was done so that no other pipe fittings can be substituted. Only a fitting specifically made to connect a propane tank can be used. This is a safety measure. Some Joe would rig up a connection with the wrong pipe fittings if they could.
I safety pin sets together and put them in their own drawer, use a basket for socks and underwear, I store onesies with pyjamas and then sort the other drawers by tops, trousers and skirts. Dresses are hung up in the wardrobe and her shoes are stored on the top shelf of the wardrobe by occasion.