Yes. In Allstar cheerleading, you get to tumble, (just as much as gymnasts do) stunt (which takes a lot of work with balance), lift up other girls (takes a lot of strength) and move quickly throughout the routine. It takes a lot of work to do all of those things. Your not just standing around yelling chants, your running, and tumbling like an athlete.
Gymnastics is a sport, and you need a high level of gymnastics for cheerleading and that helps make it a sport.