Thanks.
It's not the conclusions people come to so much as the reasoning that I often find odd.
We know from experience that we get told things at e.g. press conferences that turn out to be wrong (famous example re drone attack in Afghanistan, the US Army response was shown to be completely wrong in circs not really explicable except on the basis of 'We'll just say...oh shit, they've worked out that can't be true') so questioning the official version is A Good Thing, in my book.
But on a rational basis. And equally, if people want to shoot down some of the alternative theories, it has to be properly reasoned, not just dismissed. I looked at some of the links posted on this thread and thought, 'Well you're asking me to take a lot of things that support your theory on trust, why should I?' I don't see why if I refuse blindly to trust the FBI I should suddenly blindly trust Internet People.
This is a cause dear to my heart because I do feel that No Platform in all its manifestations (very modish when I was at university) was never satisfactory and is not at all helpful in the internet era. You have to keep having, and winning the argument. Just like with Bell Curvers and Holocaust Deniers, if you think someone is a conspiracy theorist way off base, you have to demonstrate it by persuasive analysis. And ditto if you believe the official version is wrong.
All that said, a personal disclaimer: I have a relative who is a senior US govt official. The blanket dismissal of US govt as peopled by evil murderers does really really get to me. My rellie has made huge sacrifices in the cause of public service, and he's not alone.