I'm not sure what you mean by "absence of any alerts." The stick shaker was activated. Is that an "alert"?
Not in Boeing parlance.
They had a Master Caution associated with the alpha vane right after rotation. Was that an "alert"?
Yes
The IAS Disagree annunciation appears on the PFD's when there is greater than a 5 knot difference for more than 5 seconds. That criteria was met in this case, so I'm fairly confident that this "alert" was also present.
"Fairly confident". Would you agree if the discrepancy at that stage was less than five knots there would be no such annunciation?
Despite these indications, there was no apparent attempt to cross check airspeeds even with an active stick shaker.
"apparent". ie nothing recorded on the CVR. You exclude the possibility of non-verbalised assessment?
I'm not really sure what you are looking for here, because it doesn't get any more basic than this. The signs were there. We all agree they were unnoticed. Why those signs were unnoticed clearly points to a human factors issue.
It would only be a human factors issue, in the negative sense, if it could be shown that there was a significant deviation from the performance that could be expected of an average crew on an average day. Your use of words such as "clearly" and "basic" are argumentative strategies to support your point of view but are not justified.
You are not building a watertight case.