The reason I don't think this would work is because no one knows their wifi password.
This was my thought, too - and those that do would recognize the fake control panel. I think it's becoming more and more common for the PSK to come on a sticker from the all-in-one router/modem your ISP sends you. So, the user never sets a passphrase, never sees the control panel, and has the key ready to hand out by just looking at their "internet box." This attack is perfect for that.
If manufacturers stopped using fixed length keys for a particular product line and made use of the entire alphabet it would make this kind of exercise infeasible.