Rationalize: "An attempt to explain or justify (one's own or another's behavior or attitude) with logical, plausible reasons, even if these are not true or appropriate"

Rational: "based on or in accordance with reason or logic"

They sure seem like related concepts to me. Maybe you have a different understanding of what "rationalizing" is, and I'd be interested in hearing it

But if all you're going to do is drive by comment saying "You're wrong" without elaborating at all, maybe just keep it to yourself next time