Yeah. I think it's more likely to stop someone accidentally taking the wrong bike. Since they aren't secured to anything and the locks aren't beefy, defeating it would be pretty trivial.
I have a number of friends with anecdotes about forgetting items on a bus/train and the lengths to which individuals or companies will go to return them is pretty impressive.
side note: the ubiquitous Japanese bike style you're referring to is called "mamachari"