(IMHO, Gilbert created the term "pooh-bah" to echo a toddler's lisping name for his stuffed bear)
Not so, Keiva. I wouldn't be surprised if WS Gilbert's opinion of chidren equalled that of W.Fields. Pooh and bah were common Victorian expressions of contempt. If you wished to rubbish someone else's opinions, you might well say, "Pooh to that, Sir." Bah was a rather more irate response in the same vein. Using the two epithets as a name, apart from being a crude pastiche on Japanese names, gave a clue to Pooh-Bah's contempt for the rest of the human race, who were so much more lowly bred than he.

To she of the Airy Words, Walloons are, indeed, inhabitants of Belgium - the name is also used for the language that they speak, which is very similar to French. They are cordially hated by the Flemish-speaking population of Belgium, I gather. Certainly, I have found that I get better service in Zeebrugge if I speak English than if I use French!