Why aren't black olives packed in glass jars, like green olives?

I’ve never have found black olives packed in resealable glass jars at my locality; they are always packed in non-resealable cans. But I can find green olives that are packed in resealable jars, but not in cans. Is the shelf life of black olives in glass jars a lot shorter than the shelf life is when they are packed in cans? Or is the flavor of black olives adversely affected by light exposure? Or is there some other reason that glass is not the preferred packaging material for black olives?