First, what is the importance of the fact that just about any issue of sorting out people is nowadays likely to be ideologically charged and legally dangerous? Second, what about the fact that these models are supposed to throw some high-status people out of work, and in a way that makes them look like they've been incompetent all along?

I am not sure what you think the answers to these questions are, but I would say my personal opinion on the matter is that the more ideologically charged and legally dangerous a matter is, the more important accuracy and correctness - at the expense, if necessary, of strongly-held beliefs. I would also say that protecting the reputation of competency enjoyed by high-status people is not an activity that strongly correlates with being right; I predict a small negative correlation, in fact.

Furthermore, there is a selection effect: learning the LW/OB folklore will result in you noticing specific cases of their application, and you are far, far more likely to write a post about that any about any given subject. That is, you see a prevalence of "standard bias explanation" because top-level posters are actively looking for actual cases of bias to discuss.