I’ll be honest, @HerbKraft, this is the first I’ve ever heard of such a rule. Our scouts handle much of the money at our fundraisers, and have since they were Cub Scouts. We often have an adult at the cash box, more to deter opportunistic thieves who think that a 13-year-old is an easy target than because we don’t trust the boys to manage things.
Are there some sort of a unit-level set of bylaws for the troop? This might be one of those situations where the chartering organization has a rule that they imposed on the unit, either due to some accounting thing they need to deal with or based on a previous problem with scouts handling money.
Personally, I’d ask for the story behind the “rule” before I challenged it. Maybe lead with “When the boys were Cub Scouts, they used to handle all of the money. Why does your troop only have the adults handling the money?” It might even be a council rule (or misinterpretation thereof) of which your pack wasn’t aware. I try not to simply assume it’s poor judgment just because it doesn’t make sense to me.