My contention is that most users want access to information. If they are interested in learning about X (whether it is their great-great-grandfather, their house, women’s suffrage, the Monongahela River, or the evolution of the concept of academic freedom) they want to find all the materials that pertain to X. The majority of them do not care in what record group, collection  or series those materials are located. If the archivist brought out a box labeled “all the materials on X,” assembled from all over the archives with no indication of where it came from, the user would be thrilled, not disappointed.

Is context sometimes interesting? Probably occasionally, but I would guess rarely. And I would guess only if it adds information that the user needs–such as probable date for an undated letter.