[MaxWilson]

I don't know how much I can add to my previous posts, but to recap, there are several contributing factors:

1.) Many of them don't.
2.) Just because I think the evidence is weak doesn't mean everyone will think the same. I think you can have legitimate disagreement here.
3.) There are outside pressures. Many of the ones that don't keep relatively quiet and just keep working in their own fields--not everyone is a crusader, and it doesn't pay to rock the boat.
4.) Sociological factors. Humans in general have trouble differentiating real uncertainty from statistical uncertainty, and scientific honesty is hard (but vital). This is not to say that only one side of the debate is scientifically honest (see points #1 and #2), just that there's likely to be a lot of noise in the data if you're trying to judge truth by consensus. It's much better to judge truth by evidence.

Let me turn your question around: why was Ignatz Semmelweiss a pariah for decades in the medical community, when listening to him was really in everyone's best interest? (To the extent that his discovery, today, would elicit nothing but "Duh. Of course washing your hands reduces infection rates.")

-Max