I go "dang it" when the effect triggers but it's not the end of the world for me. GT at lv80 gives you 6 plunder deny at 50% chance, that is really annoying, but i don't target people who might get an lv80 GT in the near future. If they have the ability to level it up this fast then they are active and their city defense might go over 1000, and
they collect on time. The best way to "plunder" them is to snipe their buildings, which GT can't stop at all.
My main target is always those guys in the middle. they do events and get full sets of the event building, but they don't have a crazy high defense and they collect things when they can which gives me a window to jump in the snap the best building I can find. These guys not going to have a high-level GT, even if they want to, because their FP production is quite low and it will take them a whole year to reach lv80(more or less)
So yeah, GT is kinda annoying but it doesn't affect me that much