Why do people prefer to believe the authorized version of Twin Towers, Manned Moon Landings, Nazi Gas Chambers?

Because so few of the conspiracy versions are even remotely credible, and, all of them would rely on thousands of people being sworn to secrecy and, keeping the secrets...

Evidence. And because we can think. One factor that I have found in EVERYONE I have encountered who is a Holocaust denier, Moon Landing Hoaxer or 9/11 Truther is they inability to think - they can not properly employ reason and logic to sort out complicated events so they resort to simplistic conspiracy theories where they can blame dark, unseen, unidentifiable forces for their shortcomings.

Depends on what you mean by "authorized". Many of us believe that Muslim extremists hijacked planes and crashed them into the Twin Towers, that the Americans landed on the Moon as part of the Apollo programme, and that millions died in Nazi gas chambers and concentration camps. We tend to believe what we believe to be the evidence rather than what we regard as crazy conspiracy theories followed by those we see a tinfoil hat wearing nuts. We could be wrong of course. As I said "...what we regard as crazy". Is "what we regard" intimidation? I must be really scary!

Because there's a lot more evidence to support these versions of events, rather than the idiocies of the 'Truthers', the Apollo programme being a giant hoax, or the nonexistence of Nazi gas chambers.

Because it happened?

Because we look at the evidence, and don't have the need to make ourselves feel superior with fantasies about knowing "the truth". We watched the planes go in, the rocks brought back have been analysed, and no-one has still found the missing six million. Next dumb question?

Its easier, saves a lot of hassle like reading and such also fear built up over time, i felt very uncomfortable reading stuff about Nazi gas chambers or 9/11 etc i had always taken the piss out of conspiracy theorists as they were called, seems silly now but it is commonly accepted social etiquette that you believe everything you are told, especially regarding such sensitive issues, its like all those people who fall for the Nigerian email business deals or helping gorgeous Russian girls get a visa etc crooks play on your sense of decency, nobody who wants to start a war will say, lets do it because well get some good stuff out of it and make some money no, they'll say were going to help these people and who could refuse that

Because that is usually what happened. Sometimes the facts dont suit some people and they try to air brush history.

I think hitler went to argentina after the war and died in the late fifties of internal consumption. i truly do.. footnote: time period late fifties not his late fifties,, i want to make that clear, as if i get the facts wrong i'll be accused of making them up..