>>46812442Well isn't the justification for the Silph Scope that Ghosts scare your pokemon into inaction?
You only run into Ghost mons in the wild in Pokemon Tower, where there are real Ghosts, so it makes more sense that your pokemon would be terrified. Whereas, against a trained Pokemon team, your mons wouldn't really be scared.
You can say that the same thing holds true in Johto - Gastly are around in the wild, not concentrated in one area, so they're not that scary and you don't need a tool to overcome their illusions.