When referring to 'good score', the vast majority of people look at the amount of kills and deaths a player has, not the amount of points he accumulates. What is the benefit to gaining points? At least in War Thunder, gaining points equates to rewards. This feature just creates needless hassle for the developers.
Without points, many people come to assume that killing players is the only useful thing to do, and those that main support classes may feel neglected.
I'm sure they'd receive plenty of gratification from their team for their support. Frankly, even if they were awarded points, would anyone really care?
I certainly wouldn't be bothered if I was playing as a surgeon, or whatever, and didn't receive any type of in-game reward for my efforts. I doubt I'd even bother checking the scoreboard, I'd only be interested in healing those on my team so we'd have a fighting chance to win the match.
Although I suppose that's an opinion from a purely competitive standpoint. Perhaps some of the pubs may feel a tad 'neglected', but I'm sure they'd just as easily switch class to a fighting unit if they felt that unappreciated.