I think this is more about ads then copyright. All these recipe blogs I've seen still follow with an uncopyrightable list of ingredients and simple directions. The recipe still isn't worthy of copyright, even if the content accompanying it is. Sure, the author may be working on something they are passionate about, but the site itself is all about the ad revenue.
> Recipes can be protected under copyright law if they are accompanied by “substantial literary expression.
https://copyrightalliance.org/are-recipes-cookbooks-protecte...
So the fluff is both an attempt at that substantial literary expression, and a way to differentiate this version of the recipe from 1000 other versions of the _exact_ recipe because the recipe itself is not unqiue or copyrightable! Without it, recipe's would be penalized by the duplicate content penalty Google applies.