Regarding the knives themselves: 1. Knives with one Ti scale and one plastic (i.e: FRN, G10, micarta, etc) scale; 2: Tanto, recurved and serrated blades; 3: Irregular and unreliable “quality control”; 4: Brand name-based overinflated prices; 4: Clips that aren’t deep carry; 5: Gun show garbage and the squirrels who sell it.
Regarding our world and how knives are viewed and treated: 1: Idiots who react to pocket knives as if the knives were machine guns; 2: Mindless, draconian regulation of knives (e.g: NYC, London, etc).