"You might as well broadcast"
Is that so? Granted, not broadcasting the SSID is not going to keep it some sort of inaccessible secret, but it will prevent your WiFi showing up in the list on a casual scan which is all you need to prevent 99.9% of all access attempts. If someone is staying put for long enough to methodically scan your neighbourhood and chance upon your smartphone connecting as you return home (as everything else will likely just stay connected 24/7) chances are you're up against a threat you can't even begin to hope to successfully counter. Yes, it won't simply magically keep you safe all by its own - but useless? Hell no.