The hand-mechanical is not (necessarily) obsessive.
Describing a hand-mechanical practice or approach to a piece as “obsessive” means, of course, “obsessive compulsive,” means, of course, that the artist is a little crazy. And if the artist is “crazy” then their work (and they themselves) are some sort of aberration, a mistake, an anomaly, and while the hand-mechanical process can be enjoyed by the viewer, it is not something that they can understand, because, as the product of a mind that is a little off, there is nothing, essentially, for the viewer to understand. The process becomes a kind of spectacle for the viewer to consume.
The label of obsessive immediately denies the idea that the artist came to the choice of using a hand-mechanical approach comfortably and rationally, and that that approach, that process, is integral to the concept of the piece.
(Brief aside. Concept: The overall arrangement of the entire idea for the piece. Concept contains form, content, modes of production, and modes of reception. Concept is the arranged relationship between those four things. Content: what the piece is about. Could be personal, political, spiritual, self-referential, theoretical, etc. Content is one piece of the concept. These terms are way too confused in day-to-day art discourse. (There’s a day-to-day art discourse?))
A hand-mechanical process can be used rationally, should be used rationally and logically, to examine artistic (and other kinds, “non-artistic”) labor. What are the internal qualities of a hand-mechanical process, and how do they affect the other internal qualities of the piece, such as form and content? How can the process of making affect the process of reception/distribution, and vice versa? Can an intensive process have external qualities? Does it have something to do with the world? What are the parameters that determine whether labor is artistic? What kind of labor and laborers are author-ized? What kinds of labor and laborers are not allowed to share in the act of creation? What kind of labor is agency in action, and which kind of labor is a denial of agency?
An activity that is undertaken by an artist because they are “compelled” to do so by a mental disorder is an activity whose critical capacity can be easily dismissed. (To be clear: the sentence before this is being critical of a particular critical attitude, and is not a dismissal of the work of the mentally ill as “non-artistic.” The hand-mechanical could potentially be used as a means to unpack how and why the work of the mentally ill is valued differently than the work of “normal” artists.) And so the label of “obsessive” denies the hand-mechanical, and the artist who uses it, of their agency, when in fact a hand-mechanical approach often is a seriously considered, self-effacing, critical application of that agency to the idea of artistic labor.