Exactly! How is anything ever going to be known without some experimentation, research, and sometimes death...
The fact is that fish die... Everything living eventually will not be, for various reasons. They don't even know why this one died - you do realise that there are diseases that can persist for several months (without any symptoms), then show up one day and take out your fish within a day (I personally expierienced this). Let them atleast do thier necropsy (Do you even do this when your fish die? I doubt it... (I take it people who don't care do this with thier fish) first before you start labeling them murderers... The fact is that nobody knows for sure what, or who killed this whale so, IMO, you are being extremely rude saying that about these people.
As for some things not being meant to be kept in captivity... you would be thinking that about tetras if you were to live far enough back in time...
Personally, I'm only offended that you would say that about these people... I take it you've never had a fish die, right?