Although the video going viral is a bit much, in general, I'd view the humiliation as potentially giving a positive lesson to a 14-year-old. Griefing (which I'd call obvious cheating a form of, though I don't play GW2 and don't know the exact circumstances here) is a really uniquely digital phenomenon, because you can go around pissing people off and laughing about it without any real consequences - at worst your account gets banned, and you can go make a new one - and with the separation of anonymity and limited chat tools making it easy to mentally dehumanize your targets. Now, to some extent I think griefing can be funny, especially if honed to an art like in those YouTube videos; in the majority of games where the consequences of dealing with a griefer are little more than a few minutes' irritation, the people who get most annoyed sometimes need to chill out and remember they're just playing a video game. But it also gives the griefer a power trip in exchange for behavior that would be pretty anti-social if applied in the real world. By making the griefer encounter a form of social judgement for their actions, rather than just a faceless "you are banned" screen, they're giving them a taste of reality.

Also, there's no such thing as bad press. The player in question is now infamous for this video, which I bet they see as a silver lining at worst; more ego-boosting than the hacks themselves at best.

(I say this as someone who, in my early teens, was on the receiving end of a banhammer or two on sites I really cared about; I probably remember these instances relatively well because they invoked strong negative emotions in me, which I guess isn't good, but they also made me introspect and resolve to be more mature in the future. Never cheated in video games though.)