I don't think you're grasping the concept of map control.
And you're like... Begging to give away multikills with that concept, but the whole start of this was you and others wondering why that's happening.
I think you're picturing people standing in a cluster running from point to point, which isn't what happens. People swarm to a point from all different angles then quickly disperse in other angles but all towards the next point, but able to watch for anything trying to come through. The only time people are together is at the point. Other than that, it's a thin line where everyone is a screen or so away from each other. It's trusting in a random to at least alert you with their death.