I am in continual awe of how your mind works. Your inability to grasp how data is collected, analyzed, and disseminated - and what data can accurately tell us and what it cannot - is so astoundingly wrong at every turn. Are you a bot that was created by COVID?
From the article you linked: 'While the number of cases identified is sizable—140 cases per 100,000 attendees—it is likely that the true national impact of the Sturgis event is underestimated," the report states.'
In order for those numbers to tell you what you think they are telling you, you'd have to assume at a minimum that all attendees were tested, that all were asked about Sturgis attendance, and that all gave a truthful answer. This doesn't eve touch the complexity of trying to contact trace people that would have later crossed paths with attendees. The best you can do with that kind of incomplete and imperfect data, is make your best guess as to what the true impact was. And the infectious disease experts that authored the report said it was almost certainly worse than those numbers reflect, because of course they were.