I think it also depends on the circumstances of each thing. Yes, potato chips and french fries, while they are a vegetable, are -deep-fried-. That is not healthy. (granted neither is drowning a baked potato with butter, sour cream and such.)

Air-popped popcorn is fine, but most bagged popcorn snacks are not air popped and are coated in oils and chemically created 'flavours' and usually a metric shit-ton of salt.