I think that's a known quantity. Only a child would think a bag of chips is completely filled with chips. In fact, I remember first hearing about this in some science show or something; it hadn't occurred to me before then that the bags were mostly empty, it was just the way chips were packaged.

>If you can't identify when the packaging is critical to the product, why listen to any complaints?

But you can identity it. Unless this is your very first time buying the product, you more or less know what its packaging looks like. If you buy a can of soda that's half empty you wouldn't think that it's so the liquid doesn't break.

Also, I've never heard anyone complain about the size of bags of chips relative to their contents. I've heard the explanations, but not the actual complaints. Is that something people actually do?

Complain about feeling ripped off? Absolutely. I don't buy chips much, but skin care products are the worst offenders, with both the box and the container inside having extra space to make it look like more product than it has. I don't make complaining about this my whole identity, but I have complained about items with excessive amount of air in the container whenever I've received one.