Yeah, but you don't have experimental design for the alien intelligence "hypothesis." This is just emotionally satisfying drivel. There's nothing unscientific about not having a hypothesis when more information is being gathered. The paucity of data on FRBs makes any hypothesis right now almost worthless.
We don't even know for sure that the majority of FRB data we have are from non-terrestrial phenomena. FRB occurrences at Parkes correlate strongly with lightning storms near the observatory.
But sure, it's probably angels or little green men. Why not. That's a hypothesis, you're doing science Jimmy!
So if you're observing a rain forest in Central America or a high mountaintop in South America, and you see some strange patterns or interestingly-stacked rocks, you think we should only look for non-human explanations for these things?
With this attitude, much archeological evidence of pre-Columbian civilizations would never have been found. In fact, the entire field of archaeology wouldn't exist.
Nobody mentioned elves. You're trying to make his argument absurd. We explain most phenomena scientifically and this is no exception. It most likely isn't an artificial signal, but who knows.
What's absurd about elves? If it could be little green men, maybe they have pointy ears. This is science after all, as long as it's a hypothesis, it counts, right?