It's also because that's a way of trying to copyright protect recipes, which are normally not copyright protected.
> “Mere listings of ingredients as in recipes, formulas, compounds, or prescriptions are not subject to copyright protection. However, when a recipe or formula is accompanied by substantial literary expression in the form of an explanation or directions, or when there is a combination of recipes, as in a cookbook, there may be a basis for copyright protection.”
But that copyright protection only extends to the literary expression. The recipe itself is still not covered by copyright, even if accompanied by an essay.
> “Mere listings of ingredients as in recipes, formulas, compounds, or prescriptions are not subject to copyright protection. However, when a recipe or formula is accompanied by substantial literary expression in the form of an explanation or directions, or when there is a combination of recipes, as in a cookbook, there may be a basis for copyright protection.”