That is not completely true. If you put a curser over something and it doesn't say it is a cook fire you cannot cook on it. I've found several places where it looked like an open brazier or a campfire and could not cook over it. I find it extremely frustrating running around Stormwind and Darnasis and several other areas looking for fires. (Those silly elves really do have a phobia of fire.) So I keep a stack of wood and the flint and tinder on me now. It may not be the best space use but it keeps me from pulling my hair out and running mad and naked through an unfarmiliar town.