Then let them take their chances. I'm fine with not solving their problems. Granted, Miranda would hate me for it. That's the issue. How to be unfettered, when everyone else wants you to be fettered.
Also, if I do nothing about the refugee's and civilians in your edit, what does that accomplish for me? What does it solve? Some misplaced sense of love and trust from my men, and who call me a hero? That's great, except now I don't trust them myself. I won't ever win a war with those weaklings. And I'm losing resources that I need for the people, all so I can be a 'hero'.
I'll be honest, I'd rather be a hated winner than a beloved loser.
Let's get one thing straight: Shepard, beyond roping in new allies at Hackett's behest, is not "running the war." That distinction falls on Hackett, Victus, Wrex (Wreav), Asari High Command, Koris, Gerrel, the Crucible team etc. - the people who are deciding what to protect and what to abandon, what is needed for the Crucible and how to get it, how to move things where they need to be, where, how, and if to confront the Reapers etc.
Those "weaklings" are what you have. If the person Hackett appoints to lead them can't win the war with them, Hackett is better off appointing someone else who can.
What does exterminating our own species, thus saving the Reapers the trouble of doing so and speeding them to their ultimate objective (our extinction) achieve?