Steve,
 
As a graduate student I might have a very skewed perspective on your
question and your bone to pick, but thought I would throw it out there
anyway.
 
While I see real world experience as very important in archaeology,
education can help to give people a better perspective on what the
ultimate goals of archaeology are, or should be, though that is a highly
debatable topic as well.  While I have also encountered fellow graduate
students who ask "...how that thing with the little telescope works?"
I have also met people who have spent years in the field and can
identify a piece of pearlware at 100 feet, but who have no idea what
that artifact can say about the person who made it, bought, used it or
discarded it.
 
That being said, perhaps the most important thing a degree says about a
person is that they were able to complete a standardize process.  Not
just the classes, test and research (which vary from school to school)
but, deal with the administration, school requirements and all the other
hoops one has to jump through to get the degree.   Basically, as I see
it, too a perspective employer a degree can become a very easy way rank
the applicants ability rather than having to evaluate everyone on a case
by case basis.  Unfortunately this can result in the best people being
past over for the jobs.
 
Granted this is the very skewed perspective a graduate student, but I
hope others will respond to you question.  Being in the midst of my
thesis, I have begun to wonder if it is worth it as well.  :-)
 
Rob Moon