This was a common practice in the Battle Cruiser forces of the Royal Navy. A very strong emphasis on rapid fire above all else. Examinations of the battle cruiser wrecks at the Battle of Jutland showed numerous instances of safety doors in the powder hoists wired open, empty powder canisters where there they should not have been, etc. This was not the case in the Battleship forces. Their practice was deliberate aimed fire over speed. They strictly enforced the safe handling of powders and projos, requiring all safety procedures to be followed.
While that may be the case the description of the demise of the Hood sure sounds like someone left the safety doors open.