This may be the cure in this case, but unique/automated passwords can go horribly wrong too. I once was the owner of a Vodafone EasyBox, a cheap and crappy router with pre-configured wlan wpa-keys. They looked randomly enough, but were a crude mixture of your mac-adress and router serial number[0]. It turns out, the bits of the mac adress (wich were always on the same digit) reduced the length of the unknown parts of the key to 16. The rest 65535-something key-bits could easily be brute forced.

I just had the good fortune to configure my wifi- network myself, so I had to put in my own keys. Many other people didn't, and who could blame them, they were probably happy the thing worked in the first place...

[0]: https://www.wardriving-forum.de/wiki/Standardpassw%C3%B6rter...