
Morality of destroying a planet filled with non intelligent life?
In the viltrumite war these three destroy a planet that had been evacuated of all intelligent life and presumably the viltrumites get other worlds to build their technology for them. Basically viltrum is not a super relevant military target and it's destruction serves only to demoralize the enemy(which didn't even work)
That said there had to be some non intelligent life that was unique to that planet which would be genocided by said destruction.
There is also the morality of destroying the history of that world ancient artifacts and/or fossils that would tell the story of that planet