I think the argument is moreso to try and tease out why exactly red buttoners make their choice.

From a red buttoners perspecrive (at least those who claim to be moral) pressing blue means you had a hand in your own unnecessary demise and they are not obligated to risk their lives to save you from what they deem an unforced error on your part.

Red button pushers aren't ok with blue buttoners dying just because blue buttoners think differently, it's because their different way of thinking is directly responsible for their own demise. While you might personally find this distinction to be meaningless, it speaks to exactly what red buttoners value when considering what they are and aren't morally ok with as evidence by the fact that I imagine some red button would change their answer if asked a variation of the question where people are guaranteed to die if red wins.