I can tell the difference between a knife and an ordinary item of clothing.
I can also tell the difference between an ordinary item of clothing and a protective helmet that is worn when riding a motorcycle.
I can also tell the difference between the appropriate use of a butchers knife or a crash helmet; and inappropriate use (like waving it about in the street or wearing it as you approach a cashier with a till full of money. A garment that conceals the face is inappropriate here. In areas with a history of crimes being committed by people wearing garments that conceal the face it is reasonable that they should be unwelcome.
The fact that you can buy them in shops is entirely irrelevant to them being inappropriate in some circumstances. If I wanted to be silly like you then I could say I feel sorry for you being unable to tell the difference between appropriate use and inappropriate.