[Kate00]

Did you actually talk to those teams to determine if there were no students there? I know many students who have been mistaken for mentors because they look older than they are. Did you actually look and try and see what they were doing? Maybe those "clusters of people" were just doing routine repairs, or putting things away, or tidying up the pit. Maybe their only issue for inspection was getting the robot to fit in the sizing box, and the mentors kindly offered to do the hour of filing necessary so the students could get some food and rest. Perhaps the students on the team had a curfew that they couldn't stay past - maybe their bus left early, and all of the students had to be on it. (Yes there are legal issues with mentors driving students places, unless the proper forms have been signed.)

There are way too many variables in this situation for you to EVER make a judgment about a team based on one observation. You can't judge the level of inspiration of their students by one quick glance at their pit. What you are saying is absolutely a theoretical possibility based on conjecture. You have no idea what goes on on those teams. Stop pretending to, and maybe next time go ask what's going on. The answers may surprise you.