This reflects the part that I think is not reasonable from our consumer perspective- and to be sure, I'm not arguing personally, but rather on the representation that this is the general perspective for the purpose of debate.
The manufacturer does not benefit from 'honesty' in this particular case, because the consumer is much too fickle to even begin to determine what that honesty is actually represented by. Accurate BC? Mixing production lots? Using worn dies? In practice, none of these factors matter because none can be measured in a quantifiable way. Nature of the activity. The state of the art is that some lots shoot and occasional lots are abysmally poor. The why behind the fact is irrelevant by the time the data is available because the production process has changed. Even then, most folks determine performance as a function of price tag first. Not all, but most.
After that, the physical properties of the metal do play a big part in performance. A hard material will not expand well at low velocity, a soft material will not hang together well at high velocity. Expansion is dynamic in nature as a fundamental and the whole concept of 'controlled consistent expansion' is nothing more than a marketing phrase that doesn't really describe at all what happens, but sounds nice and sells bullets as well as a high BC number does.
Brian Litz ran the numbers long ago, and the folks who can actually benefit from .05 points on a G7 are quite few and far between, so why even worry that a manufacturers number may be off by 5%?