To each his own as to how to respond, and certainly plenty of people would do as you would, and that's fine. My view of the world is that rulebreaking that adversely affects others just has to be stopped, period, whether it be Putin or a jerk in an airline lounge, and I don't really care if the offender reacts negatively to a polite request (or a firm requirement) to follow the rules; if people let harmful rulebreaking go without standing up to it, then everyone is worse off.