I don't know if it's beacuse im low elo or not (yes I know it not called elo anymore) but when people finish off champions that others are killing they are stilling raging about 'KS'.
In my opinion 'KS' does exist - Kill secured.
I fail to understand why, in a team game, players feel that they deserve all of the kills. In other games maybe only the killer gains stats for the kill, however in League, the more people who help out the better - more assist gold and xp gains.
I think this shows a larger, underlying issue with the community as a whole - enitilement. People feel that they are entitled to things based upon their role in the game, or their own person beliefs. For example, when the jungler gives out buffs (blue for the sake of ease but it applies to red as well), that only the mid laner is enitled to it. However if the mid laner is feeding and the top laner for example could use it better, then why not give it to the person who will use it to carry, not the person who is 'entitled to it', who will just transfer it to their lane partner.
This does not only apply to buffs and things of that nature, but to warding as well. I did state this in the introduction, but I am low elo - unranked actually. When I do play ADC, my team always quenstions when I buy wards. This, in my mind stems from the belief that only supports are entitled to buy wards and no one else.
Coming back to the idea of kills, people feel that just because they were fighting somebody, that they should get the kill. Even if the person was one hit away, maybe they could have done some amazing jukes and escaped. It never hurts to secure a kill, regardless of who takes it in the end.
I honestly believe that if people followed the team part of team game then the community as a whole would be better off, and that people in game would cooperate more and thus win more games.
TL;DR: Don't be lazy, read it. :P