The equivalent is a tower telling a pilot they should land and the runway is clear, except it isn't. And there also being fog, so you can't see it before it is too late. And you can magically not veer of. Planes can go around in three dimensions and try to rise again, a train basically moves in one direction, if they see the problem, it is way to late.

There is no point in the train driver making a decision about where the train goes, because he has no information for that decision. Hence it is also not his job. Like, yeah if he has reasonable reasons to think there is something wrong, nobody is going to fire him, but what is the policy that allows him to do so, while not just randomly deciding to not drive today? There is no difference for him, until he is about to die.

Pilots have the final say to refuse or stop a flight for any safety reason of their judgement... even if others tell them it is safe. And they are protected not by policy, but by law in doing so in the US and most countries.