Parables are, by their nature, designed to make you think about how you think about something. I know it is a kind of circular argument but the key is that people sometimes can't think outside the way they think. A parable is a way of bridging (sorry) that gap.
In this parable person A is engineering solutions, they are told to build a bridge so they build a bridge. Person B is solving problems, the people on one side of the gorge want to trade with people on the other. As part of the problem solution a bridge is built.
If the parable works, it kicks your thinking out of its rut for a moment so that you can ask yourself if there is something you are building/doing for the sake of doing it rather than because it solves a larger need. If you are, then you should consider what happens when you are done and everyone realizes it isn't really "needed." You can be ok with that, or not. But the key was you took a moment to think about it.
In this parable person A is engineering solutions, they are told to build a bridge so they build a bridge. Person B is solving problems, the people on one side of the gorge want to trade with people on the other. As part of the problem solution a bridge is built.
If the parable works, it kicks your thinking out of its rut for a moment so that you can ask yourself if there is something you are building/doing for the sake of doing it rather than because it solves a larger need. If you are, then you should consider what happens when you are done and everyone realizes it isn't really "needed." You can be ok with that, or not. But the key was you took a moment to think about it.
Parables hack your thinking process.