We can presume that all passengers of the trolley would prefer the trolley be stopped in this controlled manner than via a further uncontrolled collision.

Also, since passengers have never been explicitely mentionned in the premise, they do NOT exist. After all, many version of the trolley problen even go so far as to stipulate your kin relationship with the potential victims on the tracks to sway your decision.

If there had been passengers they would have mentionned repeatedly, yet they have not.

No, the only person on the trolley is the conductor, the one person with more responsibility than the switch flipping audience stand-in.

Not suprising, as a lot of scheduled public transportation travels in a state of under-utilization.

And for that reason, controlled derailment is the only moral certainty, as the fact that the trolley has no brakes is the only guaranteed fact universally included in this problem AND ensuring safe operability of the trolley is a universal responsibility of all persons driving a vehicle in public.