There are shows out there that kids love and parents enjoy too. There are also shows that kids love and parents loathe. Caillou is one of the former. While the show ended its run in 2010, it still regularly runs on kid’s channels.
Parents don’t have to go too far on the internet before they begin to run into anti-Caillou pages. The show isn’t really all that bad, but super juvenile. It will be delightful for lots of children and a horrible slog for most parents.