I think the footnote from the article covers your point better?:

  [1] This phrase originates from a quote by Nietzche:
        He who fights with monsters should look to it that he himself does not become a monster. And if you gaze long into an abyss, the abyss also gazes into you.
  I’m probably not using “stare into the abyss” in the exact same sense Nietzche intended, since I wouldn’t really describe what I’m talking about as “fighting with a monster” or like it has the potential to turn you into a monster. [snip]