Individually doing atmospheric analysis for every planet in the galaxy is probably an impossible task for a civilisation confined to a single solar system. Listening for signals is something our civilisation already does. If we discover radio signals from a primitive civilisation in the next star system over there’s a non-zero chance we’d panic and try to wipe them out.
That’s the risk that dark forest theory is talking about. Maybe the threat comes from a civilisation dedicated to wiping out intelligent life that just hasn’t found you yet, maybe it just comes from your nearest neighbor. Maybe there’s no threat at all. The risk of interplanetary war is still too great to turn on a light in the forest and risk a bullet from the dark.
And while knowing this, why do we still not choose to just observe and be as quiet/ non existant as possible?
The dangers of Active SETI are based on a lot of human-centric assumptions.
Any hypothetical alien civilisation advanced enough to pose a threat may see our radio broadcasts and space probes as being so crude that they consider us too harmless to bother with.
If there are actively “xenocidal” aliens out there they may also have far more effective ways of detecting their targets.
Disagree. The counterargument is simple - space is large and time is long. We aren’t a threat now but we could easily become a threat in, say, 1000 years. Which, is basically no time at all in interstellar politics. Any species who could potentially become a technical capable threat should be assumed as a technically capable threat.