Had we sent people to Mars instead of the satellite, and made the same mistake, it might have led to loss of life as well as being much more expensive and a public relations nightmare.
Space needs to compete with other priorities, such as defense and exploration of inner space (eg deep ocean exploration). Man has probably logged more time on or around the moon than in the Marianas Trench, for example.
The fact of the space station is that it is a solution for a problem that has not yet been fully formulated (industrial exploitation of weightlessness and vacuum). With no positive ROI in sight, and budget overruns, it makes sense to scale back the space station project in favor of other priorities (eg robotic exploration). We already have a lot of data on the effects of weightlessness on the human body thanks to Soyuz, so I believe that is not really a critical justification for increasing space station resources at this time.
While I don't begrudge the moon shots and applaud a good romantic goal, I think it is also good to keep goals in perspective.