Two things at work there:
1. Profiling or more like stereotypical-driven assumptions.
2. Cluelessness. No serious thief will go to that much public effort. If something can't be stolen quietly and in 60 seconds or less, it's a waive off. This I know from my years of work for Kryptonite locks. It's all about slowing the perp down.

When I lived in Brooklyn, I refrained from riding my bike in Prospect Park because bike thieves would hide behind big trees next to the paths and clothesline unsuspecting cyclists as they rode by. Very efficient. Knock you off your bike and ride off with it in less than 5 seconds! shocked