It comes down to a misidentification of a problem (UAS), which could have been communicated to the crew by a clearer and more expedite way.
Then the first question to ask is, "
Why would a pilot conclude that there is a requirement to act or respond in any way, before the abnormality has been identified?"
We both know that identifying the problem is a fundamental aviation principle. If there is difficulty in identifying the problem, wait. As in many abnormals which occur, there was no emergency, no need to act unilaterally, instantly. The safety of the aircraft was never in question, (that's possibly a hindsight observation). Why was action taken, vice not?, is what it comes down to I think. And this point is germane to the discussion where crews did not immediately identify or respond 100% correctly,
because in all events but this one there was no accident. Why?
I do see your point - a warning vice "circumstantial evidence" so to speak, would probably stop action and cause a change in behaviour but then the question becomes, At what point do we stop designing for such things?, and the larger question is, In terms of interventions and attention-getting, what is the balance between pilot and automation? There are within us all, the sources of an accident - do we expect that design and engineering, and then Standards & Training/SOPs/CRM/HF (SHEL), will resolve all these issues? If not, what is acceptable and why?