I say scythes is a bad example. Scythes have after all been actual weapons in proper history, unlike Kartifa knives. That makes them mutually exclusive as an example. How it's used now does not change how it's been used in the past. Plus scythes look actually threatening.

I personally don't think it's a lack of exposure that's reasoning for them not being used as weapons. I think it's their very appearance that makes them look remarkably unimpresisve as anything but a ritual object. But nice that you are using it for Yami still!