Extended Life Support - good or bad?

During my last weeks rpg session (fantasy, not D&D), our party was seperated into two groups, each one facing a relatively strong opponent. We didn't know about that, however, until it was too late. While the fighters (including me) we charging after the first enemy who had attacked us with a crossbow, the second enemy approached our rearguard from behind. Unfortunately for them, our rearguard consisted only of two magicians and a priest, who are unsuited for close combat. So what happened was, our elementarist (the only one capable of doing D&D-like offensive magic) was temporarily turned into stone by our female mind-control/beguiling mage, saving his life before she turned and ran.
The priest (worshipping a god of thieves and merchants) wasn't so smart. Although he had become invisible, he was hit two or three times, bringing him down to the "permanent and irreversible death" hit point level. The priest even saw the mythological bird supposed to carry his soul to the land of the dead, but the bird told him that his time hadn't come yet, and that the gods needed him to do some things for them before they would take him off this world.
So, after the fighters had taken care of the second bad guy, our two mages and the elf were able to revive the priest, which almost depleted their pool of astral energy.
We are playing an epic campaign composed of 20+ connected adventures. During the course of this campaign the PCs are supposed to receive 7 marks, foretold in the prophecies, making those PCs with a mark practically irreplaceable. However, the priest hadn't received a mark yet, so I didn't consider it absolutely necessary to keep him alive.
I would even have felt slightly angry, if I had been denied death like this.

How do you see this? How would you have felt in such a situation?

I'd say this hugely depends on what the player wants to do with his character.
Some players who have invested a lot in a character may want to keep it and not lose it because of a bad roll, or on the contrary be happy to see it die after a long and eventful life or in a heroic fashion.

On such occasion, I (as the player) would have warned the GM either that I had no problem with dying right now, or asked if there was a way I could remain alive (even with some lasting weakness as a result).

On the general matter of life support, I don't like the idea of characters being immortal and knowing that, no matter what, they'll escape any situation unharmed. Players have sometimes to feel a little pang of fear for the life of their characters. On the other hand, I don't like to see a character die while its player had other plan for it, and I prefer in such a case to see a character escape death, but at a high cost. In that particular case, the priest could well have survived with a nasty disability.

Character Death

As a GM I try to avoid it, but I do have rules, I lay down on that. I won't kill them unless they do something extremely stupid, but depending on the game, I have the right to maim where nessery, be surprised how many players hate being maimed rather than killed. Oh yes, I have out of all the GMs in my gaming group have killed the most player characters. If players think they can pull of some heroics to push the extreme go for it, they usually feel that is a good idea. I have had characters have to heal following the regular healing rules for the game. Man am I a bastard at times.

Here is an example like I said doing something extremely stupid: After a long lenghty battle in the Star Wars game I ran, one of the players, a Scoundrel Smuggler type, was surround by 15 Stormtroopers told to drop his weapon, while the rest of the party, one player character was seriously injured , the others 2 including the Scoundrel Smuggler were injured dropped their blasters. The Scoundrel Smuggler decided to fight firing at the Imperial Officer. Well his Scoundrel Smuggler died taking out 2 of the other player characters in the process (someone does something extremely stupid never say no one else could be killed), only one player survived and it was not the Jedi. Since we have 5 people in the gaming group the others had to make new characters. They decided let's play something else, they were to ticked off at the Scoundrel Smuggler player for being that stupid.

I have been known to 'kill' a character for a plotline such as what happened to the priest, but I agree with you. He should have recieved the mark, if it came earlier than the DM wanted, as a GM deal with it. If you are waaaay to structured, you are not ready when your players throw you a loop. I think the DM dropped the ball here, should have marked the priest modify his storyline a little. Part of the game as GM adapt. The GM could have kept him alive and let him stablize, but he could die if you do not get any real mystical help from something else. Something should have been done, doing nothing is plain stupid the whole we have plans for you gimmick without anything behind it like a vision for the next Adventure (or the one you are on) should have been an option. His character survived, but what did the group gain? GM made a mistake in my opinion.

To me, it's the GM's call.

If the PC wants his mark, he can fall on his own blade, if he wants to die so badly.

Conversely, I let PC die from anything that can cause it, it doesn't have to be stupid. And I let every player know it well in advance, I don't generally fudge anything, and "Keep a backup PC handy."

It can be, "Let's fire at the enemy ship." If the next round of combat dictates a bridge hit, and the specific system deals death to 2 or 3 Bridge crew, and medical can't save 'em, they are gone. Such is the condition of service in the Fleet.

I don't believe in game balance, I believe that if you go for a fight, people will die. Might be them, might be you. Roll the dice.

A lot of players do not like this style. Those that do, love it, because they all know, no character has script immunity in my games, and I do not have favorite NPCs.

But I have seen situations where

Enveloping Plasma has killed off 1/3 of the bridge crew, PCs and NPCs both.

A planet-eater has torn a ship in half, killing 100, including 3 PCs, and wounding 300 NPC crew.

The ship's engineer raced into a fire in main engineering, saving 3 engineering crewmen, and emerging badly burned, getting the Starfleet Cross as a result, and returning to duty months later, aftoer surgery, and recovery.

The ship's Catian Navigator dragged his unconsciuous captain off of a bridge in flames, despite his pyrophobia, both allowing him to overcome it, and saving the Captain. The captain retired at the end of the cruise, and the Navigator received the equivalent of a Silver Star Medal.

About perhaps 2 dozen PCs have died in my Trek games, since 1988. The rest were lucky or careful.