Chefs have their own language. Ask them for a recipe and they'll say, "Take some fish steaks." (What kind? How many?) "Season, sear and roast them in the oven." (How hot? How long?) "Make a beurre rouge." (A what?) "Garnish and serve." It's chefspeak, and it's not meant for us.
They don't just speak this language, they write books in it. Early cookbooks are all by chefs for chefs, and therefore take for granted a professional competence. That was truein the 14th century, when Taillevent offered elaborate spice mixes without a single measurement, and in the 19th century, when Auguste Escoffier wrote recipes (which he called aide-mémoires) that are actually complex cross-references to other recipes.
Because these books assumed a high level of skill in the kitchen, they were definitely not meant for home cooks, who need more hand-holding. I remember the angry response to Pino Luongo's A Tuscan in the Kitchen, published in 1988, which listed ingredients but (like Taillevent and Escoffier) never told how much of anything to use. Luongo, who owns several restaurants, defended himself by saying that precise measurements are an artifact, that good cooks make adjustments depending on the quality of their ingredients. He was right, of course, but readers weren't ready to hear that.