Those among Humanity who fear the worst (that the Thargoids are out to destroy Humanity) seem to discount the countless non-fatal interactions with humanity's ships. If Thargoid goodies were surrendered, ships were not destroyed.
Also, if presuming the worst, why then haven't the Thargoids simply dropped into Sol, unleashed some devastating deed there, and casually jumped away? They're presumed to be intelligent. Do we really think they don't know about Sol? That they can't follow our movements and gain an understanding of what systems are significant? 'Congregation' or 'concentration' is a simple enough metric and concept. You needn't have an understanding of much else if you're just looking to wipe out big portions of a civilization. Go where the big numbers are, deliver your unforgettable message...
It seems to me that the instances of attacks against humans are not in space that wasn't first Thargoid-occupied (or Thargoid historical) and later inhabited by humanity, or attempted to be inhabited, harvested, mutilated. Those identifications have been made by Humanity. Remember, we can't (or won't) hear any messages they might be sending.
They have not, in any significant way, expanded attacks into 'our space.' Who's got patience? This makes it look more like Humanity is the annoying insect, being almost carefully swept away from the hands that we're annoying, rather than being killed outright.
Communication? I'm not convinced that we have tried honestly as a civilization. Sure, there are groups who are trying - while being harshly ridiculed by a not-insignificant portion of our civilization.
I've not really been on one side or the other of this humanity / Thargoid epic. But, looking at it, one has to wonder if we're being honest and objective, or if we're being short-sighted, narrow-minded, and not really trying to break out of our well-known tendency to exhibit those traits.