First off, the writer spends too much time on writing cleverly than on writing to the point.
Secondly, they falls prey to their own mistake of over-simplification of the issue, summing up all Trolls in all eras and contexts - and conveniently ignoring the fact that the catch-phrase behind the article sprung from a specific one, to which it was particularly suited. It's never been a good fit outside of Forums & Newsgroups, where there is a 'Conversational' setting. IMO, Twitter isn't really that.
Thirdly, as Starflower points out, they ignore Blocking and other Mod controls.
Lastly, arguing with Trolls is ultimately pointless - it's the old saw of Wrestling With A Pig: "You get dirty, and besides, the pig likes it", so really "The biggest mistake we ever made with trolls was" validating them and their behavior. You stand up and call them on it, and you don't allow room for debate. Behave or Begone. Confronting is not Feeding.
And don't take anything they say to heart - most of the shit they say, they don't even believe, and seriously, Consider The Source...
Completely agree with "consider the source" that Wyrwolf said. Yes, if someone is being vitriolic and hateful, why would anyone want to listen to them?! I don't know if trolls realize they are shooting themselves in the foot by doing that! Maybe they are so unreasonable that they don't have enough common sense to realize that being hateful will NOT make people want to relate to their side of the argument (surprise, surprise).
I agree with everyone here..
And yes,I'm not sure that they even understand how bad trolling makes them look to other people.