Not necessarily. Let's consider this for a second.
Having some kind of backup would probably be easier than breaking whatever encryption they're using, and something like this would be a "weakest link" scenario, so anything you put would probably decrease in security.
Besides that, don't really want something a technician can just bring to you, because anything like that can be stolen or sold, so you were probably gonna have to tow it anyways.
I have no clue if that's anywhere close to the actual decisions, but it's not super hard to come up with a thought process that leads to the conclusion that the possible inconvenience of being even more stuck than usual when your car is stolen in a place where you don't have cell service is better than the security reduction of having a backup anti-anti-theft mechanism
Having some kind of backup would probably be easier than breaking whatever encryption they're using, and something like this would be a "weakest link" scenario, so anything you put would probably decrease in security.
Besides that, don't really want something a technician can just bring to you, because anything like that can be stolen or sold, so you were probably gonna have to tow it anyways.
I have no clue if that's anywhere close to the actual decisions, but it's not super hard to come up with a thought process that leads to the conclusion that the possible inconvenience of being even more stuck than usual when your car is stolen in a place where you don't have cell service is better than the security reduction of having a backup anti-anti-theft mechanism