Wayne Boatwright wrote:

I'm not saying that I'm a proponent of HFCS, but just what is it
that people are so up in arms about with it?

Altern Med Rev. 2005 Dec;10(4):294-306.
Adverse effects of dietary fructose.
Gaby AR.

The consumption of fructose, primarily from high-fructose
corn syrup (HFCS), has increased considerably in the United
States during the past several decades. Intake of HFCS may
now exceed that of the other major caloric sweetener,
sucrose. Some nutritionists believe fructose is a safer form
of sugar than sucrose, particularly for people with diabetes
mellitus, because it does not adversely affect blood-glucose
regulation, at least in the short-term. However, fructose has
potentially harmful effects on other aspects of metabolism.
In particular, fructose is a potent reducing sugar that
promotes the formation of toxic advanced glycation end-products,
which appear to play a role in the aging process; in the
pathogenesis of the vascular, renal, and ocular complications
of diabetes; and in the development of atherosclerosis.
Fructose has also been implicated as the main cause of
symptoms in some patients with chronic diarrhea or other
functional bowel disturbances. In addition, excessive fructose
consumption may be responsible in part for the increasing
prevalence of obesity, diabetes mellitus, and non-alcoholic
fatty liver disease. Although the long-term effects of fructose
consumption have not been adequately studied in humans, the
available evidence suggests it may be more harmful than is
generally recognized. The extent to which a person might be
adversely affected by dietary fructose depends both on the
amount consumed and on individual tolerance. With a few
exceptions, the relatively small amounts of fructose that
occur naturally in fruits and vegetables are unlikely to
have deleterious effects, and this review is not meant to
discourage the consumption of these healthful foods.