Can you back that up?
Single bananas tend to get damaged easier. Also I’ve noticed a phenomenon locally where people will want a single banana, but will ignore the pile of single ones and pull one off a bunch themselves, often without a lot of care, sometimes even opening other bananas on the bunch in the process.
What tends to happen is a pile of slightly damaged single bananas accumulate, and no-one buys them unless they get marked down, plus the odd open one which no one will buy regardless.
My grandfather (also worked at our store. Big family business), would call out customers on that (grabbing a single one off a bunch when he had made a nice pile of 20 single bananas 6 inches away.
What people often say about refrigerating bananas is that “The outside turns brown quick, but the inside stays perfect!” That’s only true if one’s idea of “perfect” is “firm, but still tasting overripe”. Which some people prefer, different strokes and all that.
If you’re looking to use bananas for baking or for making smoothies, refrigerating them probably makes a lot more sense.
The inside of a refrigerated overripe banana is better than the inside of an unrefrigerated banana of the same age, but either is still far inferior to a banana at the proper stage of ripeness.