You're conflating issues here. This is not an assumption of bad faith; it's adhering to what the source actually says. William M. Connolley's extemporaneous comments here are not a source; the publication (RealClimate) is the source.

This is just a frank evaluation of what the source says; RealClimate says nothing about who worked on the article or how it was written, but we know that unsigned "group" pieces are often not equivalent to joint authorship. For another analogy, consider per curium legal opinions. "Per curium" means that all of the judges or justices agreed, but it's a very different thing from all of them signing the opinion. Typically, they're less controversial cases, so one judge's clerk writes the opinion, then they're circulated for comment. But the other judges typically don't scrutinize it as closely as if their name was on the line; there are many examples of judges railing against dicta that they theoretically endorsed just a couple of years earlier—sometimes even within the same case. Unanimous opinions (where every judge signs) are different, and they reflect a higher level of collaboration, as in Brown v. Board of Education. 

The bottom line is that the source itself doesn't say who wrote it. The commentators on BLP/N seem to think this is an important distinction.  Luke