I'm certainly not excusing the coaches and medical team. They shoulder the blame
But players need to look out for themselves too. If a 5/8 can pull himself from the game for self preservation, then a player should also do the same if they feel like their head has been snapped back and they feel groggy.
It's accepted to put your hand up if you've pulled a muscle. But nobody puts their hand up if they are seeing stars. The culture isn't to do so, but needs to change, particularly with everything we read about CTE
The whole game puts all the onus on the medical staff. Which is fine, but an upshot of that is everyone (players, coaches, refs, fans) expects that it's play on if the medical staff don't say anything. That's not a strong enough system to prevent this sort of thing happening