It looks more like a CFIT, so what does a gravel kit (or not) have to do with this accident?
Nothing at all - except that more modern aircraft have much improved instrumentation, nav gear and autopilots, as Aterpster pointed out.
It's a very serious issue for those operators north of 60. Boeing still charges outrageous amounts for the paperwork to modify a 737-200 for gravel kit installation, even if the hardware is available. The razor thin margins of northern operation (very high fuel and maintenance costs, comparatively long stagelengths and low utilisation) make the economics marginal, at best.
But unfortunately, the 732 is the only game in town.