In all cases the bike had to be ridable... so what if you rendered your ride a bit less "ridable" right at the start.

I was once told a method for quick security that might work... after you stop riding, you throw your derailur lever to the highest gear and then open the quick release on the rear wheel. Won't stop anybody, but does slow them down a bit.

As for the thefts in general... every theft was from a non-bike stand situation... so only the general public is involved. The general public has little reason to even think about bikes, as demonstrated by their general attitude toward bikers anyway, much less worry about concern themselves about a possible isolated incident.

Perhaps locking your bike to a bike stand would at least involve the attention of other interested bikers and cause that question and answer thing...

I know when I recently went to a shopping center nearby, while two of us were unlocking and mounting up, there was conversation that general public would not have had.

Jeeze, die grinder, eh... they even come battery powered these days... perhaps the thief could wear a striped costume with a raccoon mask so the public could get the idea... sheesh! Couldn't believe the cop truck just cruising by... sad!