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!
If the elvish hypothesis proposes some experiments for testing and disproving it, then yes - it sounds more scientific.