The 400,000 people are people who supplies parts and services to the moon missions. These were all paid for by the government, millions upon millions of dollars and thousands of man hours.
All so they could make a set? You say you can't understand why the evidence against would be faked, but I can't understand why the landing would be faked. They spent the money, they made the craft capable of doing it, they trained the astronauts. Everything needed to do the space landing was sorted and ready.
So why then go "well, actually, we can so it, but can't be arsed, make a film instead".
It doesn't make sense.
However, if I write a book providing evidence that the moon landings were faked, I can make millions of pounds profit and make myself famous.
So on the one hand you have the US government making a moon capable landing craft and spending hundreds of millions on it (provable money spent on making a moon landing happen).
On the other, you have people who are making millions out of saying it never happened.
Do you trust the people who it has cost millions, or the people making millions? I'm very cynical, and will always say that the people who aren't making anything are more likely to be telling the truth. Lack of payback is a good indicator of sincerity.
I didn't know the Russians had landed a moon module (unmanned) until I watched the link you posted Phil. If it's in a documentary saying the landings are faked, it must be true???
Moon radiation levels are fine for short visits, as long as there's no particularly bad solar episodes at the time. A quick Google and look at the results show that this is commonly accepted scientific fact, like the Earth has gravity, the boiling point of water, etc, etc, etc.
The evidence comes for a relatively new lunar module currently orbitting the moon and taking readings to prepare for a proposed return to the moon in 2020. They wish to understand the radiation effects over a long term to plan for people to stay on the moon for greater lengths of time.