I realize you can just answer, “mysterious aliens beyond our understanding,” but why would a space probe have a mandate of either talk to a whale for 30 seconds or destroy Earth and disable everything in its path on the way to Earth?
Why? What does that achieve?
These were beings who were casually chatting, non-technologically (at least on the whales end), over hundreds of light years. Their tech is completely unlike anything The Federation has ever seen, or even imagined within its understanding of physics. Whatever it is is incompatible with earth-like worlds and anything they make, but we needn’t think it necessarily malicious.
Imagine if tube worms from a deep sea volcanic vent sent a probe to check in with a major city. Their probe would likely be toxic to anyone downwind because of all the sulphuric chemicals and heavy metals, it may set everything around it on fire if it maintains its home temps, and would likely be giving off radon in a way that would shorten neaby lives. It’s not intentional, its just their natural state.
It was destroying the ocean. How does that help the whales it was trying to talk to?