It is repugnant, whether their culture considers it so or not. I've had cultural relativism up to my back teeth, and I have no problem at all calling this wrong. It should be obvious that normalizing the public display of corpses isn't going to make people more sensitive to death.
I don't think its really about cultural attitudes towards death. It's really about the total and complete disintigration of culture and civilization, and what leaps into the breach when that happens. Western civilisation has its share of like events(St. Bartholomews day massacre comes to mind) when the mob does what the engine of the state has failed to achieve. So while the Holocaust was a civilised(sarcasm) effort to sublimate the mob's bloodlust to the control of the state(quite successful too), this event too, had its roots in the political landscape. The horror that was released simply tore away the trappings of "civilised" behaviour and showed how quickly they could be shed. I think that is the real lesson.
How does a culture with proper rituals for burying the dead, come to terms with its own impulse to destruction? First thing is bury one's dead according to the beliefs that one has. Resume civilisation as quickly as one can, it is yours. It has failed you,and you have failed it and you know it. If that realisation doesn't hurt you as you reclaim your culture you are no better than those who took your civilisation from you. And you won't find it by looking at rotting bodies. Prove you are better, by reclaiming your lives and rituals and if you forget what happened, you never really knew anything at all. And the next paroxsym is already brewing in you. IMHO
I agree with you, its repugnant, and that's without weighing in on cultural relativsm since the article states that the Rwandans bury their dead, so they are violating their own standards. The horror won't be eased by forgetting one's values so one can remember, or by dishonoring your own beliefs, to honor them.