Well quite simple really, IF we did land on the moon then what was left behind (moon buggy and equipment) would be visible through a DECENT telescope, especially as we have telescopes that can see other unviverses. Also what about the radiation belt? This part I'm not too sure about. They say that we couldn't pass through it. Another thing is why haven't we been there since? Technology has increased tenfold since 1969 so that is my theory.
I think the last time I saw such a poor understanding of science was when debating with someone who thought Intelligent Design was "Good science".