Maybe you think I'm mean-spirited in pointing to inadequate citations in a (quasi)scholarly publication. Scholars, though, should expect readers to check their citations. The basic purpose of a citation is to provide support for a claim by providing documentation of sources that made this claim previously, or to document what other scholars have concluded, even if these conclusions are ones you want to question. You can also work backwards, checking the citations in cited sources to see if they are valid too. Tracing claims backwards through the references of several articles is an excellent way of learning the secondary literature in a subfield.
There might be several reasons why I might check sources. For example, the Edward Said citation I talked about in yesterday's post seemed suspicious because I know that is not the main point of Said's book. Sometimes I'll see two citations side by side that might seem incompatible or wildly different in genre: if someone is citing Shakespeare and Talcott Parsons to support the same claim I might get suspicious. Maybe a claim seems improbable and I want to see if the sources cited really support it. In other cases, I might just be curious about what a previous author said, so I'll check out the source for that reason. Maybe it contains a separate claim that I want to use in my own work.
Overcitation can cloud the waters by making it difficult for readers to check the references, sometimes creating a false impression that a lot of serious research has gone on. Massive references can intimidate less experienced scholars. A superfluous source is one that is adduced in support of a non-controversial or over-obvious point, or is redundant or irrelevant, or doesn't quite support the claim being made. Since overcitation is not a hanging offense like plagiarism, people get away with it a lot more.
Another mistake some people make is place all references on equal footing. What if the source I'm citing is a self-help book of dubious scholarly merit? It is still a name in parentheses with a page number and a date, but it should not have the same authority. Maybe it is a book published 100-years ago. Should I cite it alongside a more recent source without acknowledging the time lag? I want to feel I trust a scholar to have made the relevant acts of discrimination so sh/e can steer me to valid sources of information. Anything that undermines that trust weakens scholarly authority.