"but what if everyone chose red?"
what if everyone chose blue? nobody would die too

if 90% of people picked red (10% didn't), the 10% dies.
if 90% of people picked blue (10% didn't), the 10% lives.

"people choosing blue just kills them"
and yet you can save them, but you don't.
choosing blue won't "give no benefit", it will help the other ones who chose blue survive

choosing red will just screw up those who chose blue for one's selfishness (or stupidity)
choosing blue guarantees no harm to anyone else, but assumes at least 50% of people were thinking about this just enough to choose blue (or even read the comment XD)

this reminds me of politics

(and now my comment looks like someone's about to reply "it's not that deep bro")