PhD in tech-writing (was These Two Matters, Matters to Me!)

[MList -at- chrysalis-its -dot- com]

I'm trying to imagine the added-value of a techwriting PhD 
(educationally and in terms of research, NOT in terms of 
yet-another-credential for the student...).   I'm failing, 
miserably.

If I bend over backwards and squint through a rose-colored 
prism, I can almost see the value in a Masters. It would 
not be, as in many long-established disciplines a higher-level 
outgrowth of an intensive undergrad course of studies. Rather, 
it would be on the order of a "certificate" such as the management 
and other programs that are called Masters of ___, but which 
can be taken by someone who studied something utterly un-related 
as an undergrad.  

But a Phud?  C'mon.

There's still tool-related knowledge (that is constantly leaving 
itself behind in the technological dust) and the basics like 
research skills, rhetoric (under various guises) and technical 
aptitude, but the first is not Phud-level, the second is part of 
a good basic education, and the third is an inborn trait that you 
bring to the table as a pre-requisite.

Is the idea to get the notion of a Technical Writing PhD into 
the public (or at least employer) consciousness and then backfill 
with content at a later date?  Or have I missed a whole rich field 
of study while being a journeyman... er... trade/craftsman all 
these years?

/kevin