They personally really creep me out. The personality types it attracts seem really impressionable and lacking in a healthy disrespect for authority. Also seem to be a lot of Wolfram types who simply ignore criticism rather than admitting a mistake. Fond of the sound of their own voice.
I mean there value in using hard rationalism in the social sciences, but science is inherently built on a model.
Models are sometimes wrong (they're abstractions and approximations - there's a reason we use confidence intervals), but that doesn't mean it's all for naught - we learn something new and continue to iterate.
(Also, it feels like people in the LessWrong space never really heard about econometrics or the UChicago/Fresh Water School of Social Sciences - ie using quantitative methods in the social sciences space, which is something they've along with CMU pushed since the 30s)
The entire movement feels like people who read Asimov's Foundation, but ignore the fact that even the Foundation failed to predict the Mule.
It also feels like the ETO in the 3 Body Problem (the Tencent version, never watched the netflix one and imo never will)