It's a point that the country needed money to rebuild (although probably not by the '70s) but I'd argue the top tax rates were lowered to benefit wealthy people and not because the country didn't need the money any more - I mean just look at our national debt. We're having to borrow to finance our public sector, which is not sustainable. Conservatives often talk about cutting the debt and "living within our means", but I think rich and poor alike would have a more pleasant society if that was done by taxing more and maintaining government expenditure than by cutting it, and with it the quality of public services.
That's how taxation is supposed to work. The number of commentators in the media and on comments sections on news websites who think taxation is like a savings account you're supposed to receive back all the value you've put in makes me despair - People who can afford to pay taxes do so so that people who couldn't afford things like medical treatment, education or even shelter receive them, on the understanding that having a healthy, educated population with homes to live in ultimately makes our society better for everyone than one where the wealthy watch illiterate unemployed homeless people die of cholera in the gutter as they drive by in their chauffeur driven Bentleys.
Also, I guess, it is in some ways a compromise for the wealthy of deciding they'll forego the Bentley if it means those people don't rise up out of the gutter, take everything they own and shoot them dead in the street. Which
does happen when a society becomes incredibly unequal. I think the problem now is the people at the top feel invincible, and they kind of are because without the means for the population to rebel (which is the reason I find myself on the opposite side to a lot of the left on America's gun control issue - I think the people should have guns, I think
we should have guns) there's not much they can do to stop wealthy and powerful people walking all over them.