Stop being so all mighty. Everyone was looking out for themselves. James only cared about Lily and Harry. I fucking told you not to make me the Secret Keeper. I basically begged you, but did you listen? Of course not, because it's all about you and we can't possibly tell Remus, right, because we don't trust him.
Has it ever occurred to you that they weren't the only ones being threatened and whose lives were in danger? Of course not, because you don't give a shit about anyone but yourself and James. At least anyone I put in danger had magic and had a chance. My Muggle family had absolutely no protection from anyone.
So you want to know how I did it? With a heavy heart and trying to balancing what chances people had against Death Eaters.