Indeed, Jis. They make the regulations that govern the (non)movement of trains under these circumstances.
This is EXACTLY why the FRA has EVERYTHING to do with this mess and has been directly involved in why some train have actually been allowed to depart. What you're leaving out is not too long ago, regulations stated a train COULD depart an initial terminal with initialization or partial initialization failure, as long as the host railroad allowed it. It could also depart an initial or turnaround location that isn't designated a PTC repair point with initialization failure.
It was the FRA's ruling that stated a train can no longer depart with initialization failure. Indeed, they even changed the definition of "initial terminal" for PTC, which flies in the face of other applications of initial terminal (e.g. cab signals, brakes, non-running gear defects.) This is likely due to the fact that despite being told otherwise, the FRA probably assumed that if a piece of equipment fails to initialize, there must be something wrong with said piece of equipment.
Anyone that is actually out in the field and not sitting in an office knows this isn't the truth, and they were warned.
The best part of this is a train can depart with PTC COMPLETELY cut out/failed state in certain locations, but if it doesn't initialize in the same area, it can't move.
Example:
A MARC train operates from Washington DC to Perryville, Maryland and turns for another train. Since Perryville has no facilities, no mechanical forces and no other equipment to swap with, Perryville is considered a "turnaround location." Considering the circumstances, the trains were previously allowed to depart. Now, the current rules state that same train cannot depart Perryville with initialization failure even though there are no forces to correct the problem and no other equipment to swap with. Meanwhile, if the same train has outright PTC failure and is in cut out/failed state, the same train CAN depart Perryville under PTC failure rules....as long as it can be initialized.
This episode will certainly help the battle that has been raging between the FRA and various railroads that want this rule amended.