FL makes the exact points that I was banned for.
As a simple analogy; like when we see in a supermarket one of those yellow plastic signs warning of a slip hazard it does not prevent a slip, it alerts passing traffic to the hazard.
Would lighting have prevented the accident? We dont know. We'll never know. We can't know; that is asking for proof of an event that did not happen.
The point is, is to improve safety margins; and at marginal costs. These cranes are re-used many times.
No one is suggesting banning rotor flights over cities or banning cranes from cities, the circumstances are that a 770ft crane was placed not just within 200ft of a heli route (H4) and a compulsory reporting point. That does not leave much margin for error, if any.
As per the notam, the crane was only lit at night. was it illegal ? no, probably not, but it was damn fool thing to do.