On two recent occasions when I had to ask for one I was told they hadn't handed them out as they hadn't loaded enough to go around. Both times the CC said they'd see what they could do and returned later, surreptitiously passed me a bag and asked me not to wave it around.

It's poor form when this sort of thing happens. How many pax don't know to ask or are too shy? Doesn't seem overly tricky to load enough plus a spare or two.