I agree with the signs of the effects you suggest re. philosophers being incentivized to disagree, but that shouldn't explain (taking the strongest example of my case, two-boxing), why the majority of philosophers take the objectively less plausible view.

But plausibly LWers have the same sort of effects explaining their contra-philosophy-experts consensus. Also I don't see how the LWers are more likely to be put in touch with reality re. these questions than philosophers.