The goal is to try and create these things without the behavior. I'm not against behaviors by any means as they help a lot and make things easier, but I myself like to do them with the core engines code structure. I know some new devs out there as well attempt to do it like this to see what the code looks like. This helps us understand coding a bit better and prevent us from making basic mistakes when making more complex systems.
Overall it just helps anyone looking to have simple mechanics without the help of behaviors. :D