Owl to the Dragon Child
I see your point, and in all technicality it is true. However, the entire point is to challenge your prowess with fire. While water can douse fire, in turn, fire can evaporate water. Given enough power and skill, any element can best another. There's little point if this hypothetical water user is pathetic. And true masters of the art would accomplish little but come to a stalemate. Not that it matters, the Fire Nation is well on its way conquering the Water Tribes.
Fighting fire with fire is harder than one would suspect--especially when Dragons are very resistant to it. Challenging a dragon with fire is...I have no words, really. To hear my family speak of it, with the exception of Uncle Iroh now that I think about it, defeating a dragon with its own element is almost...a form of Enlightenment. I wouldn't know, I can't do it.
I've never seen a dragon (I believe you call them Chinese Fireballs?). That's how far gone they are. If there are any, they are very, very few in number and hiding. A dragon hasn't been spotted in the area since my uncle slew what was supposedly the last one. Dragons are more common here, right? I'd like to see one sometime, as I have never gotten the chance beforehand.