There are many aspects to that question, I could for example say that what hundreds of people eat in a restaurant in a week has to be of consistent quality and perfectly hygienic. I could talk about how knowing when to add salt to a dish makes the difference between stale or juicy lentils. Or that a roux tastes so much better if you just sauté it for a few minutes, which anyone would always do if they just knew about it, and it's the job of a recipe to tell them.

But in the end, I dont think cooks are more pompous about their craft than carpenters or painters are about their work. They wouldn't use steel screws for wood or a broad brush for corners. It's a craft and people get angry if someone gives wrong explanations.