To me, the discussion of HET is fascinating because we have somewhat 
the same issue in political science.  For most of my academic life, 
the history of political philosophy has been relegated to the 
backwaters of those departments strongest in political science.  (I 
would say that the history of political philosophy has probably never 
been relegated nation-wide as badly as HET [& that is probably true 
is Australia, too], but then again political science has almost never 
been able to claim the scientific and theoretical rigor and insight 
of economics.)

I think that there are probably parallels, with significant 
differences in emphasis, among physics, economics, and political 
science.  If you want to do *real* political science, you don't have 
to know the history of political thought -- at least, not until 
people start raising questions about your assumptions, including your 
normative assumptions, and how your assumptions bias your conclusions 
or goals.  If you want to do *real* economics, HET is irrelevant -- 
until you start to realize that contemporary economics, while it may 
have a formal definition of 'recession,' does not have a formal 
definition of 'depression' (because contemporary economics, 
obviously, was going to make it so that depressions do not exist; so 
if you want to understand what is happening now, you need HET).  If 
you want to do *real* physics (experimental physics), then the 
history of physics does not matter; but it does matter if you are 
trying to come up with some sort of unified theory of the universe, 
among relativity & quantum physics, in which case you need the 
history of physics.

Peter G. Stillman