The mortgage example doesn't seem to violate even a strict form of rationality. The negative onflow consequences are external to the decision-maker, so a "rational" decision-maker would not consider them. Rationality assumptions have never implied anything about group decision making being optimal for the group. Much of game theory and public choice theory is dedicated to showing exactly how that isn't the case (consider the classic Prisoner's Dilemma). There are many interesting behavioral ways in which people deviate from strict rationality, and you are absolutely correct to highlight the importance of framing, emotional appeals and other communications strategies. But rational choice theory highlights plenty of (partial) explanations for the difficulty of implementing change; risk aversion, switch costs, interest groups that favor the status quo being more powerful than interest groups that would benefit from a proposed change, etc. Though the hand-washing problem is likely due to habit formation and the difficulty of changing social norms, rather than any rational optimisation behavior.