I can only speak for tech companies, but my experience is that once a company becomes large enough to hire HR people and middle management, that's a sign that money is being wasted paying for unproductive types rather than creating and improving sold products and services.
Hiring HR people because "that's what a serious, large company does" and having a certain amount of mid-tier bosses because "we [the top] need better control over what's happening down at the bottom" (read: "we need detailed control of people that have been self-sufficient and productive on their own for several years"), is an excellent time to start looking for other work.
In general, HR and middle management exist for a reason. Someone has to handle all the associated (legal) burden of having employees. There's a lot of paperwork to do, a lot of communication that needs to be handled. Same for management, they exist for a reason. Not hiring HR or management is a waste of productive time: The tasks don't just magically disappear but other people, the ones that you call "productive" will have to take care of them and all of a sudden, we developers do have less time to do productive things, such as having important discussions on HN blaming HR and management for our misery.
There's an argument to be made that HR and Middle Management should be supportive functions in tech companies and thus shouldn't have the last call, but I'd be really really careful with calling them "unproductive". I for myself am glad that the paper-shuffling tasks get managed by a dedicated employee rather than myself. I'd go bonkers in a week if they'd pile up on my desk.
Hiring HR people because "that's what a serious, large company does" and having a certain amount of mid-tier bosses because "we [the top] need better control over what's happening down at the bottom" (read: "we need detailed control of people that have been self-sufficient and productive on their own for several years"), is an excellent time to start looking for other work.