Logically, I don't see the fallacy in banning tools whose primary--if not, realy, sole--use is as a weapon, yet not banning dual-use tools, which can be used as a weapon. This is secondary to the Constitutional matter, and / or whether allowing the possession of weapons for hunting or self-defense is reasonable, which IMO it is.
The greater point is that banning the weapon is a lot easier than honestly addressing the root of crime, which is that there are people of a different skin color than myself.