Why no return to the moon? Is it because the moon is just a dead dusty rock with no real intrinsic value? Kind of like one super expensive road trip?
I'll add to Claudel's answer:
The space program was not entirely popular with all Americans. There was a backlash during the Apollo missions about the cost vs. social programs. After several missions, the public grew bored and accustomed to it, the propaganda value decreased, and NASA had to switch its priorities to seem responsible...hence the 're-usable' spacecraft.
The re-usable spacecraft was only partially re-usable and I suppose could be honestly called a boondoggle. It sucked up a tremendous amount of money and didn't ever achieve its goals of cost or convenience.
Now that we've come to the end of that regrettable era, people are talking about big missions again.
Personally, I'm not in favor of spending money on NASA. As much as I enjoy technology, I'm not in favor of the USA spending public money on space missions.