I'm afraid the paper doesn't give a concrete answer to that. The historical figures and the discussion of the Gaza War are used here more as background information or for comparison. The focus is mainly on the challenges of modern war reporting, with an emphasis on the wars waged by the US.
I, on the other hand, only mentioned this study to give an impression of how ruthlessly Israel treats journalists. Or even more than that: that this state is obviously deliberately and by all means preventing objective reporting — the reason seems obvious: in my opinion, Israel is committing crimes against humanity and is doing everything in its power to cover it up, apparently not even shying away from deliberately murdering journalists.
In my opinion, there is no other explanation for the absurdly high number of media representatives already killed in Gaza especially in comparison with other, much longer wars that also had significantly larger conflict zones.
Yes, the chart is not ideal.
However, my intention was simply to give an impression of how ruthlessly Israel prevents any reporting on what is actually happening in Gaza.
I think this comparison is sufficient for that purpose, especially since it puts into perspective the enormously high number of media representatives who have been killed in Gaza. I think this makes also clear that the reason for this is most likely that Israel is deliberately targeting media representatives with all means at its disposal – including murder.
But you are absolutely right: this would become even clearer if it were made more explicit that the enormous number of war killed Journalist in Gaza refers to less than two years while other wars were much longer and also more extensive.