I get the impression you're using 'rationalizing' to mean finding a reason for an emotion that doesn't necessarily match the true source of the emotion. This is

I get the impression you're using 'rationalizing' to mean finding a reason for an emotion that doesn't necessarily match the true source of the emotion. This is different from recognizing the existing rationale, which is exactly why it's generally considered harmful. If one gets in the habit of finding new rationales for their emotions that sound more favorable, they can also get in the habit of no longer keeping their true rationales in check, which I would assume tends to result in sociopathic behavior.