>US trademark law demands that one vigorously defend their trademark, lest they lose it

I don't mean this as a criticism of your post and it's more of a launchpad for my own, but this always comes up as "the defense" of bad trademark enforcement actions and it really seems like papering over the problem rather than a worthy explanation of anything. "It's always been awful and bad" has rarely evinced much enthusiasm from anyone and I wonder if there's any chance of changing this rickety IP system.