These sorts of patents do exist, but they are not made “correctly”. Patents are supposed to contain novel ideas that are not obvious to experienced practitioners in the field. I think I agree with your criticism, except I feel it is a criticism of the execution of the law/system, rather than the law itself.

The law itself is broken, at least when combined with trade secret law. When you look at the incentive structure, you see the no one would apply for a patent if they thought it was actually difficult for others to independently figure out or reverse engineer; it's better to simply keep it a secret, and anyone sharing it will be liable for civil action and criminal prosecution. If you believe that others will figure it out on their own anyway, then it makes sense to patent it to deny them the ability to do so. Pretty much the entirety of IP law is a farce.

The whole story about wanting to incentivize companies to share their secrets doesn't even make sense. If we want the body of public knowledge to grow, don't legally protect secrets. Make non-competes illegal and make NDAs have a short maximum time limit, and you won't need to do anything special for knowledge to proliferate. The nerds that actually make things tend to like talking about how it works.