"I know it seems like those words might mean, "I give up, we can't fix it," but that's exactly my wife's point of view - and that is what I would be validating with those words"
And you should not validate that point of view. you should not validate things that are not true.
truth: your wife is choosing to end your marriage
untruth: "there's nothing she can do to make it better".
validate truth. do not validate untruth. "validate", what IS actually "valid"!!!