I also hate MW on sandwiches and whatnot because it's way too sweet. However, most coleslaw recipes add a ton of sugar anyway. So I don't think the end result is that far off.

The primary reason that I suspect he used MW is that it contains a yeast inhibitor (potassium sorbate), which seems to keep the yeast from turning the coleslaw into sauerkrautslaw. The Colonel probably didn't understand this, but knew the results were much better.

I've made coleslaw both ways (mayo and MW) and I do think the MW keeps the slaw crunchier.