Well perhaps you should - from your perspective at least.

But the universe has lots of perspectives, so yours is not the end-all-be-all.

Another angle to consider is that if the kitten grows up, it may try to kill cute helpless mice and rabbits. And from it's perspective, you might say it "should" do that. But from the mice's and rabbits' perspectives, they probably "should" try to prevent that from happening.

The quandary is that there is no "privileged" sentient perspective whose desires are more important than everyone else's - and that it's not uncommon for one person's desires to conflict with another's.

Within a community context, we tend to have a semi-democratic approach, in which we come up with rules that, while not necessarily in the best interest for everyone, are at least in the best interest of most people - or at least that of enough people that they are able to control the community towards their desired ends. For instance, most communities have punishments for thieves and murderers. But this still, in many ways, technically just amounts to a tyranny of the majority. But this tyranny of the majority is, in fact, the closest we can probably get to a "universal" morality.

I think what mainstream monotheistic religions have traditionally done is claim that their is a single "god" who supplies a "privileged" sentient perspective whose desires effectively outweigh or "trump" the desires of all other sentient perspectives. But there is no evidence for such a being - and even if there was, there's no evidence of how we might know what their desires are.

So in the absence of such a privileged perspective, the closest thing we can have is a semi-democratic tyranny of the majority that I described above, in which a community tries to come up with rules that benefit the most people.

Does that make sense?

To be clear, I'm not trying to "destroy" morality here. There are a lot of people who will argue that there is literally no morality or meaning of life at all. And what I'm essentially trying to do is actually to "rescue" morality from this type of pure nihilism, by pointing to the one source of meaning we all actually have evidence of - the intrinsic value we all experience when having our needs and desires met or withheld.