I think the drivers should have the expectation that run-off areas will be safe if they crash. Bianchi could easily have come off at the same place owing to a mechanical failure with the same result - hitting a dangerous object that should NOT be in a run-off area.
It's all about safety, and the cost of a decent crane that could reach over the barrier is pocket change to F1...
Basically if there is double-yellows you know something happened, the situation is unsafe, hence the warnings by double-yellows, and you should always slow down. A crash or in your example a failure in that same spot could both easily be avoided if you slow down more. (The failure itself maybe not but the runoff into the crane)
Please remember, not just his life was(is) at risk, also Sutil's was at risk if he still walked there running away from the vehicle. The marshalls are cleaning up, they are at risk. Double-yellows is not without a reason, also referring to your upset about the dangerous object in a run-off area, and the focus should IMO be moved on Bianchi's fault (ignoring the double-yellows. speeding under them) rather than an unlucky timing.
The story of the crane is just unlucky and easily avoidable,
IF AND ONLY IF the driver respects the rules of double-yellows.
Improving safety would mean rules for a fixed speed in double-yellow areas. Here at the Zandvoort track there is a new introduction active since a few years in amateur motorsports. Speed limit near crash sites of 60kph. 60 kph might not be desirable for F1, but these are options to consider with different speeds. I don't like pointing fingers to organisations/people who followed protocol and then get blamed for following it. Please point fingers towards those that have failed, whatever their medical condition may be.
Dont get me wrong, I do feel for Jules, we all do and I hope he gets better soon. But if it is his fault, which the investigation shows, then he responsible for what went wrong, not the FIA, not the marshalls, not the track host, not the marshalls, just him.
Driving a car is one thing, driving responsibly is another
PS. If the full 396-pages counting report of the investigation show any contradiction to what I just said, I DID NOT READ THE FULL REPORT