The author speculated that humanity might one day be cut off from access to space due to the cascading accumulation of debris in low earth orbit.
They imagined that in the future, people would look back on LEO satellites -- as distinct from GEO satellites -- as a form of dangerous pollution.
Kessler syndrome was not named specifically, but the idea that future humans would see present human activity in space as foolish and unsophisticated was a distinctive theme. Not so much "debris bad," but "LEO stupid."
Does this ring any bells? The date of publication was probably 1990s or earlier. Google turns up some vague results, but not the precise one I remember, and I'd love to find it again.
I wouldn't say our activities are foolish in regards to space debris (aside from intentional debris from satellite kill tests... cough cough Russia). The international community acknowledges the risks of debris and even have some high level goals of addressing it. And LEOs already have required deorbit timelimes/lifespans.