Forced to stop? As far as I've ever heard, serving size for all of those things has always been set by law. It's a little weird to say you're "forcing [someone] to stop" doing something you were forcing them to do in the first place.
You can see the Code of Federal Regulations defining the serving size of chips as 30 grams here: http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRS... . For "pop" (ok, carbonated beverages), a serving is defined as 8 fluid ounces. Unsurprisingly, a 20-ounce bottle usually contains 2.5 servings of carbonated beverage. How is that the pop, chip, and candy makers' fault?