How about counting team play actions like the number of ememy ultimates counter?
Scenario:
Four of my teammates get caught in Tempest's Ultimate and things look bad. However just in the nick of time I'm able to hit Tempest with Pyro's stun freeing my teammates. Plague Rider is now free to launch his Ultimate and hes wipes out the other team getting a quad kill.
In my opinion saving my team from Tempest's Ultimate is just as important if not more so than Plague launching his Ultimate in this scenario. Yet he gets all of the gold, announcer glory, and boost to his K/D stats where if im lucky I might get an Assist or two.
I agree, you do get jipped there sometimes, but also it's not really about k/d or who gets stacked. It's about the win, so as long as you get that, thats all that really matters. And if you check Pro HoN players, most have the same if not more assists than kills.