Because you're complaining about package size as if it were hidden from you somehow. Something sneaky. The only to make it clear is to (ready?) make it clear. I suggested two ways of doing so, both of which you consider silly.
By doing so, you're saying that you consider it unethical to shrink a package. The only way for them to deal with increasing costs is to raise their prices, as far as you're concerned.
But: I explained to you that customers have certain perceptions - certain price levels beyond which they simply will not buy a product. Manufacturers know what these perceptions are, based on research and product movement data. I asked you where YOUR limit was for a half gallon of ice cream. You refused to respond sensibly.
We've covered almost every angle that I had to deal with in a series of business courses. Same debates YOU would be subjected to if you were the CEO of a corporation and your board of directors called you on the carpet to discuss profitability issues. But, you seem to think these ideas originated in the twilight zone. Do you want to continue, or would you like to discuss it in exactly the same way you would if you were working on your MBA from Harvard?