First, all bees are gamblers. They have to be. They have to raise brood at a time when there is no flow in order to have bees to gather the flow. Sometimes that flow fails. Then if you don't feed they starve. It's not their fault it fails.
Second, we beekeepers steal honey. Bees can't plan on that. Sometimes we steal based on reasonable expectations (like a fall flow) and those expectations do not materialize. It's not the fault of the bees but if they don't have enough for winter and you don't feed them, they will starve.
Certainly you can manage bees so that feeding is the exception and not the rule, but if you don't feed them you will be buying more bees eventually...http://www.bushfarms.com/beesfeeding.htm