And on a hight sure it ended!

Actually I think the second person has his or her information wrong. I just tried looking some stuff up and I honestly can't find anything about parents complaining getting Courage cancelled. The show just seemed to end after 4 seasons because that was all Dilworth wanted to do (or at least it looks that way; if you get a show that lasts at least 3-4 seasons then I'd say your show was successful enough to have lived a "full life," anything beyond that is just icing on the cake so long as it doesn't go through a Family Guy-like decay).