Big box stores collecting for charitable organizations

I don't like these big box stores that ask me if I want to contribute a $1 to some fund. You know they don't turn that money over instantly to wherever it's going, but they keep it in their vaults and make money off it until it's time to send the charitable donations in. And what annoys me even more is that I'd like to offer an explanation to the clueless checkout person giving me looks that seem on the judgmental side. "You know I give directly to X Y &Z charities every year, so this stinking dollar doesn't mean a thing to anyone other than your stinking overseers because it's more money for them in the long run."  But I never say that. I just say "No."