I'm of the mindset that overall, it should be a lot harder to kill characters in D&D.
I mean, come on, it is not even possible to have a simple death scene in D&D! If you are above 0 hit points, you are fine. If you are below 0 hitpoints, but above -10, you are unconscious. Below that, dead as a doornail. There is no room for fatally injured, need immediate medical attention or will bleed to death, but still conscious and able to talk or act. Two major tropes of fiction are the hero who continues to fight despite being mortally wounded (the dead man's stand), and the dying mentor trying to pass on some information with his last breath. Those two dramatic things can't happen in D&D, at all. Player death is usually instantaneous, and any inujury can be healed to non-fatal with an application of cure minor wounds.
I think it should be harder to kill PCs, so the status of the character is not a binary choice between alive and dead. Make injured a viable situation, which adds drama and tension. Have there be situations where normal healing magic just won't work because a wound is too severe, or a character is too badly hurt to fight, but is not yet dead and is still conscious and able to flee. Things like that would make combat more fun and dramatic.
At the same time, reducing the risk of instant death allows the ever-annoying resurrection spells to be completely removed. I hate those so very much. Let the dead stay dead or come back as undead, no easy resurrection... Let PC resurrection be the result of generous DM fiat, not a PHB granted right.
In summary, I hope the 0 to -10 HP limit Sacred Cow be taken out to pasture, and abandoned to rabid hyenas.