Well, the amount of kills you've gotten in a game really isn't that important. The scoreboard is home to bits of information that is useful to everyone, not just the individual. Now let's take a look.
The amount of time left in a game-
This helps every player see how much longer there is to a game. It helps everyone know when the lobby ends. When the pregame ends. When chests refill. It's just a useful key to everyone either playing, or spectating.
The time and date-
Now this is useful to those who are playing in full screen. The time is always helpful, no matter what you're doing. Off the top of my head, I can't think of a situation where knowing the time benefits any individual. It helps everyone in the server.
The server-
Now this is just an identification, a means to know your whereabouts in the maze of servers that is MCGamer. It just allows people to know what server they're currently in, but helps anyone who's playing.
Players-
This lets everyone know how many targets remain for then to slaughter. It's a quick updated list that benefits the players who remain and have hopes of claiming the gold, and those who need to get into a server that will soon restart/get into deathmatch.
The amount of people you've killed is simply something that would be nice to have, but really isn't important. If you really want to know that badly, just type /bug and it will show up.
That really isn't a correction though 
