Because explanations to the lay person tended to gloss over the fact that "stopping the reaction" didn't actually stop heat generation and that the core still required months of continuous active cooling until the rate of heat generation was low enough that meltdown.

These reactors were presented as fail-safe systems. It turns out that they do not, in fact, fail into a safe state. They are more like airplanes over the ocean, literally months away from the nearest safe landing spot.

The entire crisis revolved around the removal of decay heat, not halting the reactors.

Perhaps you find that to be a meaningful distinction, but most people do not. Especially when the result is fundamentally similar: a meltdown, containment breach, evacuation, contaminated residential area, etc.

I mean this in the :-) nicest possible way :-), but I don't think you 'get it'.