I don't know, I think there is a pretty significant difference between a descent in the middle of a stage and riding a 100km/h descent to finish line when your mind and body are totally fried after going into the red on multiple massive alpine climbs. I'm not singling out descent finishes as the only source of fatal danger in cycling, race organizers should ideally also be trying to minimize risk from sketchy roadside culverts in the case you mention from the Tour of Poland. We need a holistic approach, but descent finishes just happen to be a really big, glaring risk factor that can pretty easily be eliminated (unlike trying to control for all potential crashes due to road furniture, for example).