The problem is not about your high k/d or a low death rate. It is about playing the objective. One player might have went 10-3, but was he helping with the objective? Did he fail to help clear a path for rm? Did he fail to help defend the zone? Did he see his teammate in a battle, and instead of helping, retreat? Does he flee away from the tower the second the enemy approaches, or does he risk death in order to take the lead?
Once you get to the S+ level, you are never going to complain about a teammate that can get kills. What he does after that is important tho. If he goes to no man's land and starts inking territory, that is bad. If he picks up rm, starts riding tower, or helping create 2 on 1 advantages, then that is good.
This is what separates good players from great players. I'd rather have a teammate (unless they are an anchor weapon) that goes 8-10 than one that goes 5-3. This shows me that they were constantly engaging the enemy and playing creating pressure. This probably means they constantly grabbed rm, distracted the charger, or became a helpful distraction for an ally charger.
I think your topic has good points, but the numbers by themselves can be confusing.
I'm a huge NBA fan, so this reminds me of a basketball quasi-adage. A few years back, this one NBA player (I forget who) said that whenever he came home from high school games and told his dad how many points he scored, his dad would ask him, "Okay, but how many fouls did you pick up?" The idea being: if he picked up too few fouls, he wasn't playing physical enough defense.
Low deaths are great in general, but sometimes (not, not, not always... not at all), they indicate a player didn't engage the enemy enough. They weren't where they needed to be. It's a weird thing because you need to stay alive to push the objective, but (unless you're lucky or just soooo much better than your opponent) if you are pushing the objective correctly, you're probably going to die at least a few times.
Tangentially related, I play a lot of pairs/team league with my wife, who is probably a little better than the average person you'll see in turf wars but a little worse than the average you'll see in ranked. Especially when we do teams, she's always the one to carry the rainmaker or ride the tower. That's her designated role, and she picks up a lot of deaths doing that yet never complains. It's thankless and it isn't glamorous, but it allows the rest of us to do things we're good at in those modes and she isn't.
That's really off topic, though, and beyond the scope/point of the OP, but it IS an exception that proves the rule to some extent.
