seems like a sophisticated theft ring would have access to the keys for the most common guards like this, reminds me of the TSA key debacle[1]
Additionally, I'd imagine that such a tiny fraction of a percentage of cars have these kinds of locks that it'd barely be worth it for thieves to figure out how to bypass them, at least until there's more widespread adoption.
Look at it in the picture and the review pictures. They're all 'keyed' alike. It's just a single offset pin. Also one review says it just holds on with friction and can be pulled off with force.