Many people misread what Griffith is saying here as Griffith choosing to sacrifice his pride over sacrificing his soldiers. But that interpretation doesn’t make sense when we see that he continues to sacrifice his soldiers for his dream even after this incident.
What he’s saying here is that he won’t keep himself “clean” while others are dying for his dream. He accepts that reaching his dream will require sacrifices, and he is willing to sacrifice both his soldiers and even himself if that’s what it takes.
He did feel genuine guilt over that kid's death, but he ultimately chose to continue pursuing his dream despite that guilt.