I went and read up a tiny bit and learned about the requirement of showing that goodwill has been taken advantage of. You are indeed correct, sorry to come off as argumentative. It "only" took me one back-and-forth before I went and checked my facts.
Hey, if you can't argue on a HN thread, when can you argue? In fairness it looks like protection for unregistered trade marks appears to differ on a state-by-state basis so the position really isn't that clear. Plus mere use appears to be sufficient to get a modicum of protection but on a very limited basis.