To me, this is ultimately the deciding statistic in determining one's true skill in PvP. I really don't care if someone has a 2.5 career k/d but they exclusively play in fireteams with other above average players.
You will also see this with streamers a bit. They will go on some big run with a bunch of other streamers in which their worst game like like a 3.0 k/d, then they will play a solo match and go 1.1 and "call it a night... must be getting tired" ...five minutes after going 20-2 with a bunch of other solid players vs a bunch of randoms.
I just think it would be interesting and a MUCH better LFG tool for Trials. If I see someone with a 1.5 career k/d with a 1.47 solo, I'd rather take them than someone with a 1.9 career and a 1.2 solo.