All in all, this is one of the more interesting moral thought experiments I have come across. Kudos to those who say they would press the blue button. Maybe it’s the explicit act of having to physically press a button that affects their choice.
But I would submit that unless everyone advocating this position are ascetic monks living in monasteries, or planning to commit suicide to avoid negatively affecting others, this is inconsistent with how they actually live their lives.
I think most of us push the red button every day, whether we realize it or not. In an overcrowded planet with human-caused climate change leading to environmental degradation (which leads to famine, war, and the exodus of populations), our mere existence—especially living in a first-world country where people utilize far more energy and resources than the average global per-capita rate—is contributing to other people’s deaths, however infinitesimally.