I don't have WPS on my router (How else do you input the SSID/Password?) and I turn Wi-Fi off when I'm not in my house so this product would be a real hassle to setup/use.
That said if someone needed to use Wi-Fi, I'd be happy to open a guest network for them (I think my router can do that but I haven't checked).
If you shut off WPS on your router and use WPA2-CCMP with a good passphrase, there is really no concern of someone getting into your wireless network.
Both of these measures do nothing if any other device is currently connected to the wireless network. A passive attacker will still be able to see your access point (by inspecting packets sent over the air by other devices to the access point) and can spoof a MAC address to connect to it.
Or what if someone decides to hack you when you are at home?
These are not real security measures.