[Serious] Generally speaking, is philosophy a worthwhile subject of study?

[The Grand Nudger]

That's an interesting idea. That other alien species would have to be absolutely incapable of understanding human beings in that they couldn't logically deduce the same ethical positions as humanity, regardless of whether or not it agreed with them.

You really don't need aliens for this thought exercise, though. People from different cultures satisfy the setup and..fwiw, we have a somewhat spotty track record in that regard - not necessarily in understanding, but in agreement, at least.

This is something that philosophers and social scientists are actively researching. As I mentioned before, it turns out that our ethical statements can be mapped and predicted. If the aliens (or any other people) can do math, they can figure out our ethics. I'd also like to point out that you've casually dropped a pregnant assumption about there being no universal ethics. We think that's untrue, obviously by reference to our very different groups since we have no aliens to refer to - but also by looking at proto-ethics in non human species. Any living creature is going to have at least some of the same interests and concerns. Hominid or cephalopod. Earth or Planet Blip. Biologicial relativism is, itself, something we understand, and it's not beyond the pale to think that some other creature similarly possessed of the ability to think about these things might understand the same. Biological relativism is, itself, a suggestion that a certain range of ethics are universal across living creatures.

Mind you, you may be right, but you might want to tighten up the delivery, as it stands you've suggested directly contradictory things to explain why you think what you do. If biological relativism is true, then ethics is not limited to our species or our biology. It certainly doesn't seem to be limited to us even between the species on this planet. So that's a rough spot. Incoherent, and counterfactual.