When I watch others playing video games

You keep track of your k/d.

I find that to be sad.

That and my SPM.
SPM is more important on Battlefield, but it's easier to raise.
Also, I hate the guy in your gif.

Score and K/D are terrible ways to show skill. Its averages.
I for one enjoy fucking around a lot and it obviously drops averages.
In my experience, most people who keep track of score averages are jerks who like to brag about their e-peen.
(Not saying you're one of those, just that it is the average experience.)

I find crushing my enemies enjoyable. So K/D and SPM is a good way to show how I play.
Plus, since it's an average it can be an indication of how well you do in your games, and whether people should look out for you or not.
Everyone plays different and some people are more anal about their stats then others.

I enjoy crushing people who annoy me too. However i find it more enjoyable when they underestimate me because my k/d and spm are low and make me look pathetic. Then they get a knife in the back and start raging.
Too each own i suppose.
They're not even that low either.....

I enjoy having a reputation and living up to it.
I find it funnier when people go after me, but end up getting their shit smacked.

I don't see the point in keeping track of your K/D.
It's just points.