The 36-year-old explained in an interview with L'Expresso (via Jeff Garcia of News4 San Antonio) that the difference was the role he was offered with the team, as well as the allure of playing for team owner Michael Jordan.
"When Michael Jordan called me, my idol, I thought, let's go," Parker said. "For me, I feel like closing the loop, to finish my career in his club, it's something special for me because it's him that made me want to play basketball."
"The Spurs offered me the same thing (contractually) as Charlotte, but it was more about the role. It was not a question of money. And it's important that people know this, because there are a lot of people who were 'angry' at the Spurs, thinking the franchise had not offered me anything. Yes, they offered me something similar, but I did not want to finish assistant-coach. And that was the role they offered me, when I wanted to play."
Parker appeared in 55 games last season, but he came off the bench regularly in the second half of the year for the first time in his career. He also set new lows with 19.5 minutes and 7.7 points per game last season.
The Spurs have been trying to get younger and let Patty Mills and Dejounte Murray take the majority of minutes at point guard.
Although Charlotte won't likely provide Parker with the type of starring role we have seen in the past from the six-time All-Star, he should get reserve minutes behind Kemba Walker.