Why is the assumption "governments are rational" more reasonable than "governments are irrational"? Both seem equally possible to me, given the fact that we don

Why is the assumption "governments are rational" more reasonable than "governments are irrational"? Both seem equally possible to me, given the fact that we don't have the information to tell, either way. In any case, that's a false dichotomy. Governments are not uniform entities, and there's no point talking about them as if they are. Governments, like people, do some rational and some irrational things.