How does configuring an enable secret password help protect a router from being compromised by an attack?

Actually, wifi systems are very vunerable to attacks from external threats even if you put a passWord on it. Even though wifi is pretty old itself, it doesn't mean it's advanced in security. People can hack into wifi systems very easily. Though, if you go to your wifi settings, you can look at all the computers connected to your wifi, the activities their doing, and even their IP addresses. So to answer your question, configuring a passWord won't really make a difference.