I've never been really big on player characters dying in my games. I think it can be one of the weakest forms of failure and often times - depending on the system - the death can be meaningless, if not completely random.
Typically, the response I see to the notion that death isn't interesting is along one or two lines - notably, that if there's no chance of a character dying it is actually taking away player agency to some degree, and can break suspension of disbelief. The game becomes like a FPS where you can just reload and keep going.
The thing is, I've never taken death off of the table in any of my games - I just tend to try to set up situations where fights to the death, or sudden random death, just aren't the best or only option. It, of course, hasn't prevented character deaths completely. One of the most intense PVPs I've ever witnessed was in one of my old Tribe 8 games, where one PC was slaughtered by another PC who fell under the influence of a Z'bri's Atmosphere, who himself was killed by a third. The entire situation was in control of the players, and at no time was death guaranteed even if it was the only logical conclusion from their actions.
|It also looked a lot like this|
As for breaking suspension of disbelief - most of the means that are used in systems to damage, hurt, or kill characters aren't exactly bastions of realism. At the best they're highly abstracted and overall subject to a lot of gray area, and at worst they're not really tied to anything remotely realistic (falling damage is often a huge violator here). I'd argue that more often than not, game systems result in lethal injuries far more often than would happen in reality, or have unrealistic break points that go from "not-lethal" to "lethal".
In the face of trying to balance odd-ball damage results with suspension of disbelief, I'd rather have some means that makes character death an option and a conscious call (by GM, player, table, it doesn't matter) than a stringent case baked into imperfect rules. Sure, going down to zero hit points or not being able to soak incoming stress or whatever should remove a character from a conflict and result in generally complicating their life a lot. But the only choice shouldn't be, "You die", and that's the way I've played for quite a long time. As far as I know, my attitude about character death hasn't garnered any complaints from my players.