The meteor that wiped out the dinosaurs 65 million years ago was a cataclysm. We lost an entire portfolio of advanced, impressive animals. Evolution had been tweaking and multiplying dinosaurs for 165 million years before and suddenly all that evolution was almost totally eliminated (birds being the living survivors today).
From this view, that was a tragedy. But for us, things worked out alright. Our ancestors at the time of the dinosaurs were pathetic little scurrying rat-things that sulked around in the shadows and didn't dare even evolve bodies big enough to be worth the dinosaurs' time to hunt us. With the Dinos out of the picture we mammals were able to spread and diversify and in time we get humans dominating the planet.
Or consider viral immunity. It's all well and fine to say something like "europeans had developed immunity to smallpox, so the virus comparatively swept like wildfire through the First Nations communities in the Americas." That seems, for the Europeans of the time, to be a pretty good thing, this immunity, but we know that this immunity was paid for with human lives, untold thousands/millions of Europeans dying at a young ag and thereby removing themselves from the gene pool. Each one of these stories is a personal/familial tragedy. Is mass death less bad if it happens spread out over time? - and even if you still claim it was "good" for the europeans to have evolved immunity, was the effect actually good? Was wholesale destruction of the indigenous peoples in the Americas actually good for Europeans? Was it good for overall human history?
Imagine if smallpox and other diseases hadn't decimated the people living in the Americas - The different groups from present day Canada down to present day Chile may well have been able to resist the European colonizers, or at least slow down and/or require more diplomacy throughout the colonization process. Maybe we humans would have been better off if the colonization of the new world was characterized by a healthy resistance to the domination by European traditions. Maybe it would have even been cooperative - A few interesting and seemingly "good" things are possible: slavery could have been curtailed much earlier, countless cultural traditions likely would have not been lost, humanity today might not have to deal with the same ugly scars in its social history and perhaps we'd all be better off because of that.
In the end, it seems pretty obvious to me that there is no such thing as univerasl objective morality, and this is a real big problem for humanity. On the other hand, if there was such a thing, that would maybe be a bigger problem for humanity because of the issues this brings up with free will, etc.
