Yep often its a matter of using default or easy passwords.I have gotten into so many routers in the past by guessing the password.
Things are mostly getting better by the manufacturers realizing that users can't be trusted to set things up properly, so some of them have started setting randomized passwords and then printing the password on a label on the bottom of the device. Good luck tho when you visit them and ask "What's the password for your wifi", there is no way they remember that random jumble of letters or get one of those "There is a password?" or "The neighbors smart kid fixed my computers internet when it didn't work"