The trouble is that people jump to the alien angle because it's interesting, then get angry with the scientists when it turns out to be mundane. I don't see this so much as being frustrated with people who are interested, but rather being frustrated with reporters who take something relatively mundane and blow it into a big story, setting people up for disappointment.
And actually, the linked post gives several satisfying explanations. They don't know which one is the right one, but that's not the same as "unexplained." If you see a flash of light in the night, it could be car headlights or lightning or a transformer explosion. It could be aliens, but the mundane explanations are enough, even if you don't have enough information to choose one in particular.
I agree with your point in general, but I'm not sure "unexplained" means the same as "having no explanation". After all, you can "explain" any phenomenon by mass hallucination of everyone who's observed it, or simply chocking it up to an extremely unlikely macroscopic quantum fluctuation. To decide whether something's a satisfactory explanation, you have to look at the a priori probability, not just how well it fits the facts. We don't actually know the a priori probability of detecting life, so it's hard to compare it against the also unknown probabilities of various other previously undiscovered astronomical phenomena, like the proposed "swarm of comets" around Tabby's star.
All that being said, in this case the fact that "SETI@home has seen millions of potential signals with similar characteristics" does imply there's nothing in particular here to get excited about. But you know, all those other signals could have been aliens too...
And actually, the linked post gives several satisfying explanations. They don't know which one is the right one, but that's not the same as "unexplained." If you see a flash of light in the night, it could be car headlights or lightning or a transformer explosion. It could be aliens, but the mundane explanations are enough, even if you don't have enough information to choose one in particular.