KIPP, whose 242 schools make it the largest U.S. public charter school network, is retiring its national slogan, “Work hard. Be nice.” The reasons for this are thought-provoking, and of personal interest to me because that is the title of the 2009 book about KIPP I spent eight years reporting and writing.

“Word hard. Be nice” was borrowed by KIPP co-founders Dave Levin and Mike Feinberg from their friend Rafe Esquith, an amazingly energetic and creative fifth-grade teacher in Los Angeles. They altered Esquith’s preferred wording, which was “Be Nice. Work Hard.” Those values were key to Esquith’s award-winning teaching and important in the Hispanic and Korean cultures of his mostly impoverished students.

A July 1 KIPP announcement said the slogan no longer described what its schools were trying to do. I see that as a sign of the Black Lives Matter movement’s growing influence. A memo from KIPP Foundation chief executive Richard Barth indicated that a change had been considered for some time. The organization said students performing at one big KIPP event had said: “I’ve been told I should just work hard and be nice. That it’ll pay off in the end. I’ve worked hard and I’ve been nice but the nice guys finish last.”

The announcement quoted a former KIPP student saying: “Asking us to ‘be nice’ puts the onus on kids to be quiet, be compliant, be controlled. It doesn’t actively challenge us to disrupt the systems that are trying to control us.”

The slogan “supports the illusion of meritocracy,” the announcement said. “For example, in the words of Orpheus Williams, who leads the Foundation’s equity programming: ‘The slogan passively supports ongoing efforts to pacify and control Black and Brown bodies in order to better condition them to be compliant and further reproduce current social norms that center whiteness and meritocracy as normal.’ ”

I have interviewed hundreds of teachers, students and staffers at KIPP since 2001. This is the first time I have heard any of them criticize the slogan. Their concerns faintly echo the views of KIPP’s most prolific critic, Jim Horn, a professor of educational leadership at Cambridge College in Massachusetts and author of the 2016 book “Work Hard, Be Hard: Journeys Through ‘No Excuses’ Teaching.” In his book, Horn said that white enthusiasm for KIPP harked back to the Hampton Model of industrial education that “came to embody a systemic method to indoctrinate and pacify the freed black population” after the Civil War.

Esquith said he conceived the slogan for a mission statement to create a charitable foundation supporting his work. “I wanted to teach the kids about Empathy. Respect for all. Compassion,” he told me in an email. “BE NICE does not mean BE DOCILE. My students are feisty. They are often in trouble with teachers because they challenge them. But they are NICE. They respect everyone.”

More than 100,000 children are enrolled in KIPP. About 90 percent are from low-income families. Fifty-five percent are black and 40 percent are Hispanic. Among KIPP teachers, 45 percent are black and 16 percent Hispanic. Thirty-seven percent of KIPP principals are black and 11 percent Hispanic.

Esquith, Feinberg, Levin and Barth are white, as are Horn and I. But a black person was essential to the establishment of KIPP. Her name was Harriett Ball, one of the most magnetic and imaginative teachers I have ever met. She taught across a hallway from Levin his first year as a teacher in Houston 28 years ago. She became his and Feinberg’s mentor, showing them the chants, songs, games and other methods — all of which she attributed to God — that made her a classroom superstar.

Her emphasis on hard work was not unusual, but her focus on being nice was. She told Levin and Feinberg they had to restrain quickly any students teasing other students so everyone felt safe and secure in the classroom. It was a rare insight.

Ball died in 2011 at 64 after a heart attack. I am not sure what she would have said about retiring the KIPP slogan, but she loved Levin and Feinberg and defended their work. She declined their plea to join their venture because she had four children and couldn’t take the financial risk. They were always quick to say Ball taught them how to teach.

KIPP said that the old slogan “is being removed from our website and our brand guidelines” but that a new slogan has yet to be approved. They should consider one of Ball’s favorite sayings: “All children will learn.” She strongly preferred that to the popular “All children can learn,” which she considered too passive.

Ball told me that when God indicated it was time for her to set up a teacher training business, she appreciated the celebrity Levin and Feinberg had given her. She said some people she knew were saying her former trainees were “stealing from black people” and “stealing your stuff.” To that, she replied, “Baby, it’s free advertising.”

Slogans are important. It will be interesting to see what KIPP comes up with. The old slogan was not my first choice for the book’s title, but the publisher liked it. If KIPP wants to tear off the book’s front cover, that’s fine with me, as long as it stays on shelves so students can read it if they want to.

Correction: A photo caption in a previous version of this column incorrectly identified Dave Levin as the co-founder and superintendent of the KIPP Academy in the South Bronx. He is co-founder of the KIPP public charter school network.