I think this is the idea — we and our technologies are so different (and compared to their own technologies, so small) that they didn’t really get that those were technologies, or markers of sapient intelligence. At best, “anthills”. Only in this case, the ants came out to talk to them, shocking them into a change of perspective (as I’d like to pretend we would change ours, if ants suddenly came over and directly communicated with us). But we wouldn’t and don’t expect it, even though ants have complicated societies and build complicated structures. Likewise 10-Q re the Milky Way species.
(Yes, I know someone’s going to post a Phase IV thing…)