I have worked as a handler and the one thing we need to avoid such accidents is - time. Normal procedures are to go nowhere near the plane before all propellers are stopped and no strobes are flashing. Actually we were not even allowed to go through the propeller arc when the engines were stopped.
However, it is a rather rushed environment and when you have an arrival and then another plane to attend to twenty minutes later, well... the temptation to get those stairs in place and the GPU connected before the propeller has stopped is there.
Also, some captains have this habit of leaving (forgetting?) the strobes on for a long time and then complaining that we don't get them on the blocks fast enough - since we are waiting for them to turn off the strobes. My company was very understanding about this but I can imagine that handlers elsewhere are less fortunate in this respect. Also, again there's often the problem that another arrival or departure is scheduled just after you have taken care of the current one so you don't want to be standing around doing nothing.
I would have hated to have strobes running in the vicinity while at work. It is rather stressful. There are enough flashing lights on the ramp already. Besides, I think the ground controllers and the tower would have a thing or two to say about having aircraft all over their ramps strobe illuminated.
All in all, thanks for your concern for our safety but, as with many human factors issues, technical solutions will do nowhere near as much good as a more relaxed work situation.
Cheers,
/ft