I don't know where the hypothesis that Miqo'te are short lived came from, as I can't find anything that suggests they might have a short life span compared to other races. It seems like reasoned speculation that somehow entered RP fanon around here.
You could deduce that perhaps many of them die young because of their lifestyle, but that isn't indicative of their natural longevity.
You could deduce that perhaps many of them die young because of their lifestyle, but that isn't indicative of their natural longevity.