I have never heard of a bike theft motivated by disdain for bikes or cyclists.

The problem is that a bike can be its own getaway vehicle. And they're small and thus easy to hide. That's why bike theft is a bigger problem than other kinds of theft. Crime is way down in NYC and Boston, but bike theft is still as bad as it ever was in the bad old days.

I still sometimes travel without a lock. I run into a store occasionally, and leave it out. Before I do that, I sabotage it by undoing the QRs on the wheels and sometimes the brakes. I push the shift levers forward so the bike will shift when pedaled. Of course, it's important to remember to undo all that before I ride away.