> people must be at liberty to disagree
Yep, but in the Science category, they should be disagreeing on a scientific basis. E.g. if AB existed back in 1998 ...
A: Have you seen that new paper by Andrew Wakefield in The Lancet?! Wow!
B: Yeah, I can't believe they published it. Look at the small sample size, the uncontrolled design and the speculative nature of the conclusions.
A: But it's in The Lancet! There's got to be more to this ...
... and you can see a good discussion kicking off. A scientific one.
There's a very big difference between a scientific approach and conspiracy theories. Conspiracy theories happened to be the subject of The Infinite Monkey Cage (BBC Radio 4 science programme with Brian Cox and Robin Ince) this week (hmmm, coincidence???) and anti-vax featured heavily:
https://www.bbc.co.uk/programmes/m000dfqn
The two threads I was involved on recently ...
* Climate change
* Anti-vax
Take the second example .... the anti-vax posts were being given as much credibility as the pro-vax posts, as in "All opinions are equal". But they're not. If you have more members who are anti-vax on a thread, and all opinions supposedly count as equal, then AB is not doing what it's set up to do.