Your standards for acceptable K/D are unreasonably high.

No my standards for myself are high. The people I want to play with have even higher standards than me.

Match score in Destiny is largely determined by kills. For team playlists this means that, if you get more kills than you are killed, you gained more points than the other team gained from you (in general). This equates to any K/D greater than 1.0. With a K/D greater than 1.0, you were an asset to your team by netting positive points.

Right so there's a bunch of players dragging the team down, which means hopefully there's players that can pick up the slack and people that barely have a 1.0 K/D aren't picking up anyone's slack.

Obviously, the higher your K/D, you prove to be a greater asset, but that doesn't mean a K/D of "1.0-1.5 just means you can at least aim".

Since this is my first shooter, and I don't even own a console I started out at like a 0.7 K/D. Sat just under a 1.0 K/D until January. The reason it was that low is because I was losing gun fights due to not being able to aim properly. The people I beat mostly can't aim properly either. People I play against that have under a 1.0 generally make bad decisions and lose easy gunfights.

Conversely, using your example of a K/D of 8.0 and going 8-0, is nothing to sneeze at. That person played defensively and did nothing but contribute to the success of the team.

Not necessarily. I've played in six mans as someone that goes 10-0 and believe me I didn't contribute anything since they were going to win by a landslide anyway. I've also had games where lost going 12+ kills at 4.0 K/D and I didn't contribute anything either. I currently play with people trying to get Mark of the Unbroken and they're ending games 7-0, 8-0, 12-0 and I can feel they aren't contributing in the least. Someone with that score is not going to go out and win the game for you. Recently I played as a 3 man with people with really nice stats and lost a few games to a four man since my teammates were more interested in K/D than winning.

The point is, as long as you're above a 1.0 K/D, you're an asset to your team you're doing great.

That's cool but some people aren't satisfied with the minimum, some people want to push the limit.