Why would a pilot on final to a towered airport not speak up when ATC clears another aircraft to land on the same runway, without mentioning them? Every time I watch AOPA's Accident Case Study video Communication Breakdown, I'm left wondering. Here's an aircraft (in this case, '1DA) on final approach for landing on a towered airport, when another aircraft ('4SR) is cleared to enter the traffic pattern, and gets cleared to land before they turn base, without ATC mentioning the aircraft already on final. One could make an argument that the pilot of '4SR should be aware of '1DA, but somehow, they apparently weren't. Once the pilot of '4SR is made aware of the traffic already on final, they make what I can only describe as a hasty attempt at an evasive maneuver which results in '4SR crashing into the ground, killing everyone aboard '4SR.

Yes, this is a towered, controlled airport; ATC should be the one to inform the incoming aircraft about the one on final. But for some (here unimportant) reason, ATC fails to do so.

To make matters worse, '1DA is flown by a student pilot and instructor, so there's two people there, either of whom (and certainly the instructor) can use the radio.

In such a situation, why wouldn't the pilot of '1DA speak up?

'1DA was still some distance out from the airport. It seems to me that besides the obvious of maintaining situational awareness, there were several rather obvious options available here:


No later than when the pilot reported being on base, ATC could (maybe should) have instructed the pilot of '4SR to make a right turn to re-enter the downwind leg, and to then extend downwind and land behind '1DA. Yes, reentering the downwind leg from the inside would be unusual, but it seems as though it would have kept them well out of the path of '1DA on final.
ATC could have told '1DA to go around when the controller realized that '4SR was unaware of '1DA, allowing '4SR to land ahead of '1DA; things could be sorted out once both where on the ground (the video mentions this possibility).
The pilot of '1DA could have made a position report specifying being number one on final for the same runway, when ATC didn't mention them to '4SR.
The pilot of '1DA could have aborted their landing and executed a missed approach, announcing this, effectively letting '4SR land ahead of them.


Any of those (and probably a few other) options seem like it could have prevented the accident altogether, at the cost of a relatively minor inconvenience to either '4SR or '1DA. So why would no one do anything until it was (obviously in retrospect in this particular example case) too late?
why wouldn't the pilot of '1DA speak up?


The simple answer is that you are not trained to "speak up" at a towered airport, you are trained to follow instructions from the tower and there is an assumption the tower will provide separation and appropriate clearances. As an ultimate fall back you are always supposed to "see and avoid". 

For the official report you should reference the NTSB report but if you listen to the ATC audio in the linked video as well as their explanation of the link the pilots had no reason to think there was an issue and the clearances given were rushed but explicit. As I note above AOPA also notes 


  "it is a pilots responsibility to visually confirm final approach"  


You can also hear that the pilot of '4SR was giving confusing instructions about base extension and clearance to land. The pilots was not incorrect in his approach actions but made a critical go-around error and may have been a low altitude, dirty config, stall.    

Ultimately the lower aircraft on approach had the right of way so '1DA had no reason to speak up as they were in the right. AOPA states that the pilots may have thought "he was overtaking the aircraft from above" which is incorrect, or at least procedurally incorrect as '4SR would have had to yield to '1DA anyway. 

In the end the controller should have simply issued 


  '4SR Go Around


Any time, you as a pilot hear that you should build the habit to just go around. As PIC you can ALWAYS execute a go around, controllers should be prepared for it and more importantly you as the PIC should be prepared for it.