For the record: "product" was not anyone's root metaphor when the
process/product dichotomy was created by process people during the
"sixties." "Product" is a derrogatory term/metaphor invented by
those who opposed it. That is, a metaphor designed to direct
attention to what is wrong with the "current traditional" / formalist
approach. So it is not surprising that "product" has undesirable
implications (as Russ points out).
Nonetheless, there is a crucial distinction (that I have, as
Doug suggests, made various times in the past) between those who
believe in process-for-process-sake, the value of which is largely in
what students discover/learn in the process (i.e., a very valid and
valuable kind of school writing, writing to learn), and
process-for-product sake, where the value of working on writing
process is that it leads to writing that works (i.e., to a completed
piece of writing [a.k.a. "product"] that effects/influences readers).
In the latter case, the assumption is that if our students learn
certain processes used by "effective" writers, they can use those
processes (e.g., heuristics, audience analysis) to make the writing
they produce more effective (i.e., more likely to accomplish their
purposes with their intended readers).
The attack on "process" in Australia, like the mid-1970s
attack on "creativity"/"during" that literacy "crisis," was an attack
on process-for-process-sake. And the basis of that attack was that.
whatever its educational efficacy, it did not lead to the kinds of
worldly writing abilities students need for purposes other than
self-discovery. (There were other bases, e.g., "back to the basics"
too, but that's another story.)
At any event, to foist a derrogatory metaphor on a faction
and then critique the implications of that metaphor seems somewhat
tautological, even if we do it because we have forgotten the source
of the metaphor. "Current traditional" formalism has enough of its
own to critique. And "genre" approaches are in constant danger of
being reduced to decontextualized formalism in the hands of students
looking for a quick fix, teachers who don't fully understand, and
conservatives who want the reduction. (But that, too, is another
story; cf., again, Australia, which the "technology" of linguistics
is a major contributor to "teachers who don't fully understand.")