It's like having 12345 as the code on your luggage.

To be fair, there's really very little point to having a code for your luggage. The amount of added security it gives is laughable.

It's basically just there to dissuade casual pickpocket/theft.

Like if you're traveling by rail and have your briefcase overhead and are snoozing, someone could just open it, take your laptop and disappear.

That's about the sum total of cases it's preventing. Not terribly useful, no.