Why do people say it.s to hot on mercury to support life, and to cold on pluto, are we all so narrow minded?

just because we need oxygen and an atmosphere doesn't mean every life form does. there could be planets out there with sulphuric acid seas and toxic ges every were, but life has managed to evolve in a different way than ours and getting on just fine. is it possible that they don't need to breath, its only because our bodies are so flimsy and weak that we need nice clean air to keep us going. what do you think?