Many, gnome and otherwise, believe that, by ways and for reasons unknown, Thermaplugg actively sought out the troggs, perhaps in an attempt to "stage" an invasion in order to both humiliate and defeat Mekkatorque and simultaneously portray himself as a rescuer and savior of Gnomeregan, thus insuring himself to swifty claim the throne and title of High Tinker... but the troggs were not so easily controlled.

The leper gnomes, and possibly Thermaplugg himself, have been mutated and driven insane from the effects of the radiation... the lepers reliving the "fall of Gnomeregan" all over again, seeing any who set foot in Gnomeregan as invading troggs who must be stopped at any cost, while Mekkatorque himself, in his madness, believes his plans a success, and that he is the new king of a reborn city.

As for the present of the Dark Iron dwarves in Gnomeregan... that is a mystery - perhaps they are trying to overpower the maddened lepers and their delusional king to establish the city as a secret base close to Ironforge, or maybe studying the radiation for use as a weapon... or perhaps something even more sinister, who can be sure?