I thought so too, but the other side of the argument is that it ignores hits of less than s6.
I would go ahead and say that gauss can wound grotesques though. If it can Immobilize a Land Raider I don't think it should have too much trouble with some goth masochist.
I know you already agree, Monster Rain. But I wanted to reinforce it by pointing this out:
Even a target which the weapon could not normally hurt
because of it's high Toughness or because it is immune to weapons below a given Strength is wounded.
So as you've emphasized "hits". Well, weapons cannot normally "hit"(hurt) Grotesques. That's why Gauss is the Superman of weaponry.
I know this is all semantics, but it is very important that all Necron players understand these things if we're to make our strategies work. We don't have too many options as a whole, so rules are important.