The fact that we all experience people mowing down the enemies we’re in melee with (super common, even when load of other enemies to shoot at) makes me think that getting the kills does matter to a lot of people. Maybe everyone just wants that frame with the skulls (I sure do).
Maybe getting the “red cross of death” or announcement of killing a special etc is enough of a seratonin hit to make people want it more.
I don’t think there is any way to change the way people play due to the game being so intense and mad, but a minor tweak to how deaths are registered could be a nice little mechanic imo.
As an ogryn I experience this issue A LOT. A single swipe never kills and second swing is so slow that they’ve all been shot before I get to swing again. It’s just a frustration as it sucks a bit of the joy and satisfaction out of it.