Probably because Peter was being entirely too hard on himself. He'd dealt with some really heavy stuff in the past few years and seen more trauma than any teenaged boy who wasn't even through with high school ever should have. He made mistakes. And then he tried his hardest to fix them. It was enough. Peter should have been able to go on that field trip without having to be Spider-Man. He should have been able to take a much needed and deserved mental break without someone forcing him into it. He'd done enough.
"Kid," he said plainly, rubbing his fingers over an eye and wondering, vaguely, if there'd ever be a time in his life again where he didn't feel just kind of tired. "We're both alive for me to hear the story at all. I can't possibly be disappointed."