NASA, like other government programs might hire a butt-load of scientists and engineers - but in the end it's run by administrators, who are political appointees, and they get there by knowing which way the wind blows. And, there can be very little doubt which direction that breeze has been coming from in the last few decades.
And even if they don't believe it, they might just be saying that to 'sell' the program to people who think that's the only reason to do anything.
I've never heard a scientist claim any sort of moral authority with regards to being a scientist. I'm sure most of them feel that they are moral people - even the ones who design nuclear weapons - but that is not a result of science.
And the best reason I've ever heard for doing this kind of research and exploration is because we're going there. We're going into space, so it's good to know where we are going.
By the way, most science uses, and has used metric measurement for a long time now. It's political/cultural deal why that conversion wasn't fully implemented, but it's in effect in about half of things that use such things, like soda being sold in liters. There is some thinking that part of the original trouble with Hubble came from a metric/english conversion problem, but its far more likely that the problem was just that we had never tried to do that before and the effects of mirrors and lenses being made in one gravity level and then placed into another caused a bit of a warp. Whatever the reasons, they were fixed, and the results are among the most mind-blowing things I've ever seen.
http://hubblesite.org/gallery/And the total cost of this is a very small part of the federal budget.
