This is silly. First, I don’t think anyone has ever literally claimed that non-intervention was some kind of foolproof guarantee that one would never be a victim of any sort of terrorism, so adducing a counterexample as a gotcha for the “naive” interlocutor in your head isn’t exactly a knock-down. Yeah, we’ve all heard the story about the teetotaling vegetarian who exercised every day and then dropped dead of a heart attack at 35. That doesn’t constitute a brief for the health benefits of sloth and debauchery.
But that aside, how great a counterexample is this really? The target of the PFLP bomb was an Israel-bound flight, which is to say, it was a way of attacking Israel that happened to strike a Swiss target That’s no consolation to the people who died on that flight, certainly, but in terms of assessing the motives of terrorists and determining how likely any particular country is to be a victim of future attacks, it is relevant. It’s not, for instance, that Switzerland was made a primary target just by dint of being free and secular. No Swiss pundit could seriously claim the attack as evidence that the fanatics are determined to kill the Swiss no matter what, as we see American pundits arguing that intervention is beside the point because the jihadists want to destroy America no matter what.