Actual outsiders or people inside who for whatever reason can't fit in, will always see any community system that is tight knit around a specific shared goal and belief as being 'cultish'.
Sports locker rooms are absolutely up there with the best of them in terms of groupthink, because you fail without buy-in. That's why the leaders try to eliminate outside distractions and have clear messaging, values, expectations, etc. Same is true of churches, the military, bands on tour, etc.