It's related to how electrical is set up in the game. As I said, it's very basic and not intended to be realistic. This setup lets you use two sensors (or more) to open a door, for example (if placed in sequence) while also allowing them to turn each other on or off if something is between them. If you were to wire them normally, a sensor would turn the next sensor on/off and if you wanted to make it so either can work to activate the door, you'd wire them in parallel, which isn't possible in this game. So yeah, it's intentional. Many of us would like a better electrical system in the game -- I'd be happy just getting a full set of logic gates -- but this is what we have.