To sell them individually they could sell them by weight and have it calculated at check out, just like the bunches. Actually, I think you can do that at stores here; take what you want and they calculate the cost based on total weight.
I feel that vegetables, fruit and such, and especially bananas, grow their own packaging and don't need more except when transported or stored in bulk. Individually packaging bananas (again) and printing labels adds to the overall cost in materials and through paying employees to take them out of shipping boxes, weigh them individually, package and label them, then set up the display. Additional products could be put on display in the space wasted by this. The only benefits would be reducing bugs and the chance for additional losses due to them rotting and such, and taking a bunch with them.
I still think it is absurd, and not just for the reasons I listed (although it is quite telling about the state of the world when every last little natural thing sold is modified, wrapped in plastic, labeled and can probably be found on a shelf in a store in most parts of the developed world). At first I was amused by it, but now that I have more thoroughly analyzed it I feel it is quite wasteful. I also think I don't like something about this.