Also although a lot was known about the Moon before Armstrong took those first steps, nobody could be absolutely sure what it would be like or what minerals resources, if any, might be present there. Ditto space walks and whether we could function in zero gravity. So science can tell us some things about unknown environments but until enough evidence is gathered which has to involve people getting in close sometimes to explore and experiment and build the knowledge base, before you can turn around and say - this is what we know we're going to find, as far as we can be sure...
If we'd known that there's very little viable reason to go the moon (as in its a pile of rock that mostly isn't worth the effort or expense to mine or populate) we would never have bothered going there in the first place - we had to go see it 'properly' first to establish that. Now we know more about it science will eventually make it worthwhile for us to go back again when there another reason and less effort involved in getting up there - or send robots or automated AI machines? At present space commerce is viable because we need to get satellite's up there and can do that fairly easily now as we've had a lot of practice - going to Mars is the next step perhaps because there's atmosphere and some water and so you get the next question of whether terraforming is perhaps a possibility so maybe that's more likely as the next manned mission to gather more evidence....
So on this rare occasion Bush was probably right and maybe even a little too optimistic - for now it's not worth going back to the Moon for so little at such cost when there's so much more down here to sort out...