or even when you draw an Exorcist dead with Gear (save Exorcist and an Estate)
What would it mean to draw a Night card dead?
I meant that because Night cards can't be drawn dead, it's often better than opening Gear + terminal action. With Gear + terminal action you have to set the terminal aside and play it next turn. With Exorcist, it's likely to line up with Estate right away and if it doesn't you can just set your Estates aside for the next turn.
Of course you'll still probably set the Exorcist aside if Gear draws it with 5 Coppers, but buying a $5 and guaranteeing a Wisp on your next turn is better than buying Silver, trashing the Copper with Exorcist for no benefit, and having to wait to draw it again. Copper is pretty useful in the early game, especially if you've quickly turned all 3 Estates into Wisps.