We (the USA) went to the moon for a lot of reasons, but the biggest one was that the development of space technology was seen as vital to our national defense. High-flown Kennedy rhetoric notwithstanding, the decision-makers were pragmatic men, and not particularly visionary; what they really wanted to do was develop technological capabilities superior to those of the Soviets and other potential adversaries. In fact, the advances brought about by the space program -- in satellite communications, computer technology, guidance systems, and other related areas -- are absolutely critical to our military position in the world today. Other countries have also benefited from these advances, but in military matters, what really counts is staying a step or two ahead of the other guys. More than anything else, that was why we went into space. The moon race in particular provided a well-defined mission around which to organize these efforts, and a "happy" rationale that the country could rally behind.

As for spending our money on space vs. spending our money on Earth, where do people think the money goes? It goes to the companies and individuals that are contributing to the mission; which means that it goes to technological and industrial development, and to the salaries of the men and women who work for the companies that are part of the effort, helping to contribute to a robust domestic economy. NASA doesn't just collect a bunch of money and shoot it off in a rocket; it stays right here on Earth.