The issue is that Tatum is the clear leader of team. If he starts with the posing and the victory waves to the crowd, the rest of the team will pick up on this. It is unnecessary distraction that you never saw from the likes of Larry Bird. Bird would make an out of this world shot and before his feet hit the ground, he was already scheming to steal the ball or make some other defensive play.
Yeah, the team is certainly playing like they're distracted right now.
Call me crazy, but I think Tatum is setting the tone just fine. Respectfully, yes, you do sound very "get off my lawn" right now. Playing like a robot doesn't work for everybody. Giannis flexes and mean-mugs after dunks. Curry shimmies after threes. Lebron, Luka, Trae, Embiid, Durant, Mitchell... all of these guys showboat to the crowd when they're feeling themselves. I'd have a much harder time making a list of players who DON'T do it. It's basically Kawhi and that's it. I don't want these guys to act like they don't have a pulse.
Look, I'm not advocating for this to turn into the NFL, where tackling a guy for a 15-yard gain is grounds for a professionally-choreographed dance by the entire defense. Excessive celebration can be... well, excessive. I just think Tatum blowing kisses to the crowd as he runs back on defense is a long, long, long way away from that.