Interesting question!, found it to be a matter of where your personal and professional time-line is. At first think we all strive for or were directed to duplicate a recipe, consistently. After you gain more experience that begets confidence and ability think "we" wanted to see if we could duplicate while improving the original, I did so while making a lot of mistakes! Then you get one or two or more right that people like, then you think, hey! this is good $hi+!, people like it, it sets me apart from the crowd, and it's Mine!
Be honest, who doesn't love, l-o-v-e, love to see guests smiling and really enjoying something you've just put your bs&t and basically your soul into making. It's a momentary but very gratifying feeling, no?
Plying the "dark arts" of "cooking" is IMO, an art form, therefore by definition subjective and open to interpretation. How a professional chef interprets a recipe can be the difference between financial success or failure but in either case will set them apart. If you are successful and your interpretation brings financial rewards, then business 101 demands you keep it to yourself.
EVERYONE I socialize with has their own "secret" marinara, gravy/spaghetti, BBQ sauce, chili, pickles (Hey D!), burger and rib recipes to name a few. Know restaurants that have handed down recipes to their successor chefs for decades, literally.
Have found the most inspiration and advice from retired or soon to be retired chefs that now cook when, where and how they want to. (homage to "clam bar Lou")
I'm compiling my originals and of course personal takes on some classics and new classics for a cookbook, so been pretty close to the vest except for friends and ask only if they use them to give credit when due. We make spice blends that use as many house made components as possible, e.g. smoke/flavor our own salts, pepper corns, cheese etc., in various flavors, have specific growers for our American Espelette and paprika (have not used commercial "red pepper flakes or commercial paprika for a LOT of years) dry and or smoke & grind, flavor sustainable hardwoods for our tasso, bacon, sausages, pastrami etc. among others.
Not shy at steering or giving out the basics but will keep the nuances and techniques "secret" until we finish the book!
"Ars Est Celare Artem"