Former competitive basketball player here, still play pickup regularly. "Nobody who has ever played even semicompetitive organized basketball could mistake this for an honest performance" is blatant hyperbole.
I could not possibly disagree with you more re: 1984 Lakers/Celtics, and I'm a huge Lakers fan who'd love to believe they were really the better team. I'm not going to bother to click on the video, but I'm sure you're referring to Magic dribbling the clock out at the end of game 2, and throwing the ball away at the end of game 4? These are called mistakes, and they get made all the time. Steph Curry threw the ball away similarly with a needless behind the back pass in game 7 2016, almost exactly the same as Magic's game 4 (although with a bit more time left in the game). JR Smith utterly forgot what the score was at the end of Game 1 last year and did exactly the same thing as Magic in 1984 game 2. These examples are just from the past few years, there are countless others. I'll also point out those 2 examples are both from the NBA finals. If you just want examples of professional players throwing bad passes resulting in turnovers or dribbling too long resulting in time running out, the former happens about ~10 times in every single NBA game, the latter happens a couple of times per week during the regular season.
You're talking about the highest pressure situation in the sport, players make mistakes. You are sorely underestimating the competitiveness of these athletes. I defy you to watch any interview Magic gave in the 80s and to this present day about the 84 finals, and still argue that he threw the series on purpose. His first NBA finals matchup with Larry Bird, who had been his rival for 5 years at that point, going back to their college careers? Either he's the the world's greatest actor, or that loss emotionally and mentally devastated him for a year until he got redemption in 85.
You say the league needed the white fanbase's team to win, and it is absolutely true there was a huge racial component to the Lakers/Celtics rivalry in the 80s. How do you then explain the 85 and 87 finals? I consider myself pretty knowledgable about NBA history dating back to the NBA/ABA merger, and to be blunt your comments sound very uninformed.