There, I Fixed It
the theory behind the captioning at There I Fixed It was that the gate latch was added to the car because the numeric code (see that panel above the door handle? that's for entering a passcode) is too hard to remember.
the thing is that the gate latch isn't a lock, it's a latch. if a latch alone was good enough the owner could simply close the door and not lock it (also, you can still use traditional keyed entry judging by the keyhole). it appears that this car door is in such a state of disrepair that it won't actually latch properly and needs to be held closed with this additional hardware. so the true moral of the story is that both security technology (the lock) and the infrastructure it works with (the door) need to be maintained or they won't do you any good.