I might say "oh, no, this is not necessary--you should just settle with the satisfaction of knowing that you helped your team win that round; you don't need a number". As CrazyCracka points out, it is very possible to feel good about, and be recognized for your contribution towards the team's victory.
But then why have a k/d counter? Why even count the number of times your team won--isn't it the fun of just playing that matters, or of just taking joy in the individual victories rather than their sum?
I think the issue here is competitiveness. Yes, your score is just a number, but it's symbolic of something more, something that hits at the core of why people play games. I like to see my awesome k/d up there, at the top of the list, above the scores of everyone below me. I like to know that I've been exactly X amount useful to the team, and I sure as fuck want everyone else to know, too. It's one of the reasons I keep playing, and I don't really think it's a toooo bad a thing. Competition does, of course, become an issue when, as in Huey's case, you play only to win. And it's entirely selfish when it's not being projected outward to encompass your team's score.
So, I believe an assist counter would be fair to those classes of player who lend assistance to their team but do not get rewarded with many kills, as is symbolized in the k/d ratio. The issue here is, as others have noted, what exactly constitutes an "assist". Perhaps a damage counter and a kill counter would be a nice compromise? The k/d is, I think, a very nice thing to have--it clearly makes out the deadliest players of both teams, and hits home harder than a huge damage counter statistic. Still, some sort of recognition for The Helpful Ones should exist, and a simple damage stat would do (including damage done to mounted horses, if possible).
I'm biased though, because I'm an OP lancer cav bundle of sticks that pads his k/d with the corpses of the unwary and naked/unarmed.