Why follow TCAS?
Just to clear up one point here - the TCAS issues instructions to both aircraft involved in a confliction. The ATC may do if they have time - or only to one of the aircraft.
Disobeying TCAS can well lead to an escalation of the situation.
If nothing else comes from this tragic mess, let us at least learn that TCAS is the master. That is how it was conceived - and if it goes off with an RA, there is precious little time to question its motives.