Question: do your school systems have other disciplinary measures besides suspension/expulsion?
In Romania, we have a distinct grade, called "Behavior", which by default is a 10, but you can get points subtracted. It influences your final yearly grade of course, but more important, if you don't have perfect 10 in all your school/highschool years, it can disqualify you from pursuing certain fields. For instance, you can't go to police academy or military if you've had even a single 9.
@Humpleupagus
Luckily it's rare that it actually happens. You need to do a bit more than just get into a random fight for your grade to be affected. I think it either needs to be a repeated behavior, or something explicitly planned.