I like what you posted - the quote of Robert Kennedy. By definition: GNP is: An economic statistic that includes GDP, plus any income earned by residents from overseas investments, minus income earned within the domestic economy by overseas residents (citing investopedia.com).
GNP includes also public and private services, such as healthcare, policing and so on, pretty much anything. It is not a psychological or cultural index, I guess, but on the other hand, it is a powerful economic index. I am not sure I understand Kennedy.
Thank you. It is likely I have missed something.Respectfully, I think you're over-analyzing it and not seeing the GDP as symbolism for <insert physical thing we use to measure worth with>. You're just not seeing the correlation to positive psychology.