...on his bench? He didn't all of a sudden become a hard-case disciplinarian only AFTER he became the coach at UNC. This is a trait that is part of who he is as a coach and why his teams have had a culture of winning and success no matter where he was coaching. The title of his autobiography is "Hard Work: A Life On and Off the Court."
It's a part of who he is and why he's a great coach with 3 National Championships, 2 NCAA runner-up finishes, numerous Final Fours and Elite Eights. It's why he's the 2nd winningest coach at two historic programs (Kansas and North Carolina) with two legendary coaches (Phog Allen and Dean Smith).
Establishing the culture of your team isn't something you do when it's convenient. That culture is what draws great players to your program. Winners want to play with winners.
Look at the culture that Mark Few has established at Gonzaga. He now has great players flocking from all corners to be part of his culture of winning. That wasn't always the case but what was always the case was his teams played hard on both ends of the court and set egos aside to build a strong team.