How distracting can a Master Caution Light and a segment light be?
One pilot is supposed to be flying the machine....always.
On an Approach such as the one in question....one Pilot is supposed to "driving" while the other monitors the other Pilot and taking care of "stuff" that arises.
Even though the Autopilot is "flying" the machine....the Handling Pilot is looking for correct function and performance.
There is far more to this crash than meets the eye here.
What it is shall be explained probably by what the CVR has to say.
Why were Target Air Speeds, ROD's, and MDA's not monitored. Any deviation from the Target or selected speeds/rates/altitudes should have been detected and corrected.
Why the deviation is less important than why the deviation was not detected and corrected. That will be the key to this puzzle.