At what point in a quest do you "call it" as either being hopeless to think you can complete, or that it will take so long and so many resources to complete (if you even can) that it just isn't worth it?

I am generally pretty patient. Today I was in a quest that is generally fairly tough on elite at-level, and we started off fairly poorly. The first room with significant mobs killed four or five of the party members, mostly because they all just ran in immediately and were overwhelmed. I used a clicky to raise the cleric and he got everyone else up. I mentioned that this quest can be tough and we can't just run into rooms full of mobs, and it seemed that everyone agreed with me.

At the second room with a bunch of mobs, everyone ran in again, with another four or five deaths as a result. I mentioned again that we can't just run into these rooms, and I spoke up for the cleric, who was being somewhat berated by another player for not casting Mass Heal. I pointed out that the cleric was level 16 and didn't have Mass Heal yet.

We get to the third room with a bunch of mobs, and once again everyone runs in. I think there was only one death at first, but then someone runs past that room, down the corridor, and aggros a bunch of other mobs and drags them back to us. More deaths, including my one for me, resulted. At that point I recalled, said, "Thanks anyway, guys. I've got to go," and I dropped group.

I then received a series of tells from one of the party members, calling me names and threatening to report me for "abandoning quests."

Is there some point for you when you "call it" and try again later, or are you the type who will stick with a PUG forever, no matter how unintelligently they are playing and no matter how ardently they refuse to change demonstrably fatal tactics?