It's true that people sometimes behave instrumentally-irrationally in the sense that they don't take the correct steps to reach their goal of happiness. But that fact, alone, is relatively weak evidence: people are a little irrational, not completely wrong about what makes them happy.
Your reply can be read very generally ("behavior is not always rational, therefore it's not positively correlated with desired results"). Please specify what you meant more precisely.
I'm saying that the argument that most people are doing something is not proof that what they are doing is better. In other words, the fact that most rich people choose not to give away all of their fortune is not proof that being rich is better than being poor. Why they choose not to give it all away cannot be inferred from their actions.
Personally I would state that this is a false dichotomy and that Rich is better than Poor because it is not-Poor. It isn't necessarily the best state of not-Poor.
Another month has passed and here is a new rationality quotes thread. The usual rules are: