I guess you base that surprising "half" on the transparent analogy with politics, and so you think real-world Democrats will press blue to assert their Democrattiness. This is probably true. However, since this is the internet, and being a Democrat is associated with being online and living in a city, there are probably more than 50% blue-pressers, as shown in the poll. Just like in the real world, you won't change that ratio whichever way you vote in the poll. If swaying opinion is within a voter's control, then your "choosing" is meaningful but the "half" becomes meaningless. If swaying opinion isn't within the voter's control, it's "choosing" that becomes meaningless, and the fate of the half is already sealed by cultural forces beyond our control.

Technically for red to win the number of dead people will be between 0% and 49.999% of the population.

The entire reason to campaign for red is to reduce the dead percentage.

I don’t see them as selfless I see them as unintelligent.

Or choosing blue allows them to feel self-righteous while not actually at any risk since this isn't real. Virtue signalling is the ethic of our day.

Bringing rationalism - or whatever - clouds the discussion.

Blue is purely a win-win for me, so it's rational to only choose blue. Reds have their own value judgement.

"Rationality" is a useless quality to debate here.

but in the original dilemma you have an advantage by taking a choice at the disadvantage of the other.

But there is no advantage here to pick blue, nobody should pick blue because if we all pick red we all win.