Another Way to Think of Team Deaths/Enemy Kills
It's obvious to anyone who pays any sort of attention that when you go on kill streaks, you're worth more gold to the enemy team. On the flip side, when you have tons of deaths with no kills, you're worth less and less, until you're really only worth the same as a baby krug.
Say you're 0/5, haven't had a kill but given a few deaths so you're feeling a little down. Next team fight, you try hard to secure a kill, and end up 1/5. This is good and bad. Good, because you've (hopefully) killed someone to get your 300 or more depending on their streak, but bad because you've now reset your kill value and since you were 0/5 to begin with, you're probably one of the easier ones to kill. So now, instead of giving a negligible amount of gold to the enemy each time you die, you're back to giving a full amount. Unless it could be prevented, it's probably better this kill goes to one of your team's carries and you stick with the assist gold.
On the flip side, say you see an enemy at 0/5 and each time you run into them it's an easy kill, but gives next to nothing in gold value. If it's at a time where it WON'T severely hurt your team, you could get "outplayed" in a 1v1 and reset them at 1/5 to make them actually valuable for your team again. Only a good idea, again, if it won't result in a throw and you're not on a kill streak of any sort. Sure, it gets them more gold to actually getting somewhere in their build, but chances are the 0/5 member on the enemy team won't snowball from a single kill. (Bonus points if you were one of the ones with a lower K/D on your team as well - lotta gain for minimal loss)
I can understand why this might be something plenty of people disagree with, as giving up a kill can result in throwing a lot of the time, especially in low elo. Plenty of others also won't want to remain at a low K/D even if they have stacked assists. But, I think it's something minor to consider.