Not necessarily true. As you yourself said:
They might take the high road and choose blue as well.
I only hope you blue button pressers aren’t in charge of the group I belong to.
And I hope they don’t put you in charge of a group I’m not in.
I’m saving the whole planet. Red is killing half the planet.
They might. But you are risking death for everyone in your group by predicting that. You are gambling the lives of everyone in your group on the possibility someone else will decided to gamble the lives of everyone they know. That’s a very dubious risky bet, that will likely kill everyone in your group.
No, in the “1/2 the planet” case you are risking the life of 1/2 the planet. The only part of the planet whose life is in your hands, are being killed by you pressing blue. If the person in charge of the other half decides not to kill their half (by pressing blue), then you have just killed the half you were responsible for.
The fact you are in the half whose life is in your hands doesn’t make that the right call morally or logically.
Why not? His decision wouldn’t affect you in any way; only your own group leader’s decision to press blue or red can do that.
Edit: I misread @Kron 's post he wasn’t suggesting pressing red. My bad 
In this variant it’s the murder-suicide button
Incorrect. If he chose red (which he’s suggesting he would do) and my group leader chose blue, it would affect me greatly. In that same scenario, however, if he chooses blue…
So you admit this isn’t a fair scenario and you’ve purposely stacked the deck against blue?
I mean yes, it is not a fair scenario. If any dopers have rigged a series of billions of murder buttons, and are about to kidnap the entire population of the planet to force them to press them, I would strongly suggest they knock it off immediately! It’s an extremely unfair thing to do.
You have coyly avoided this crucial bit:
It’s a (rather silly) hypothetical scenario that clearly could never happen in real life. It’s in no way “stacked” against either red or blue it’s just a small variation on the original. It’s not “stacking” anything I’m not even sure what that would mean. No one is betting real money on this.
If he chose red and your group leader chose blue, it’s your group leader’s fault you died. Your group leader could easily have chosen red. If he had, then nothing the other leader does could impact you.
It means creating a hypothetical that strongly favors one outcome over the other. Example:
Press the red button 5 people die
Press the blue button 5000 people die
This hypothetical is stacked against most people pressing blue.
In my original hypothetical, the obvious choice is not so clear. Blue button pressers were acting altruistically (they believe) and the red button pressers were claiming that this was not a rational choice. Most of the alternate versions posted so far (as far as I can remember) have been to sway the blue button pushers to red.
It doesn’t change the fact that his decision affects me.
How so? Nothing has changed about the original hypothetical. The results are the same, the die/live cut off is the same. How is collective pressing as a group “stacking the deck” versus individual pressing?
OK, I’ll bow out of this tangent of this discussion for now because I guess I’m confused. If nothing changes, and the results are the same, I fall back to back to my original question;
It really didn’t, though. He chose not to risk killing himself and all the people he was responsible for. It’s not his fault that your group leader is more concerned about self righteousness than about the lives of everyone he is responsible for.
As an apparently “self-righteous” person I am going back the OP of this thread. It differs from the original premise mainly because in the original premise there is zero chance that there would not be minimally a sizable minority choosing blue, so the one and only way everyone lives is if blue is the majority. The extreme version presented here, just two deciders, has a realistic chance that if one chooses red the other player also dies and that there are no blue folk to be killed. I still choose blue even when is only two groups for reasons explained already, barring further data like we are grouped by some sort of kin or tribal connection, but it is a harder choice.
Down to a billionish each group, divided into eight, I’m back to a bit more solidly choosing blue. Thing is that not only does it need to be at least 50% of the groups choosing blue, we the coin flip to be in the majority. But it is highly unlikely that red will save all and I want that chance. Smaller groups more comfortable yet.