What the book DOES say is that you should not create such a fear of failure that no-one will set stretch goals, and that OKR results should not replace individual performance evaluations. In short, OKRs are what you seem to think they are, plus the culture that makes it possible. If an organisation doesn't get that right, are they doing OKRs?
If your organisation does not allow developers to push back against impossible objectives, do you not perhaps have bigger problems that OKRs (or any other system) can't fix for you? Why would you blame OKRs - would any other system not also be painful when a company has become so dysfunctional? Also, did you know that all objectives don't need to cascade - some can be set bottom-up?
You're going to call No True Scotsman fallacy, and I'm going to call Straw Man, so I'm done with this thread. Perhaps I just fell for John Doerr's elaborately constructed fantasy that he uses to sell books. But right now it seems like a useful tool to keep a company on track, and I'll keep adapting it as the company grows.