Businesses generally understand the benefits of having a workforce that reflects the diversity of consumers. That helps in designing products that make sense for those users, while keeping their own employees engaged and motivated.
Diversity isn't just a buzzword -- companies with a blend of employees tend to outperform those that are more homogeneous, according to research from the Center for Talent Innovation. That may explain part of the problem at Twitter (TWTR), which is suffering from a withering stock slump this year as well as increasing scrutiny from its user base over its lack of employee diversity.
To be sure, Twitter isn't alone among Silicon Valley companies whose engineering ranks consist mostly of white and Asian men. And the company, like many of its rivals, has vowed to improve diversity. But Twitter finds itself at the eye of the storm following an essay by former Twitter engineer Leslie Miley, who wrote this week on Medium.com that he left the firm after struggling to argue for diverse hires and to make sure the company's few black employees were included in office events.
With his departure, Miley, who is black, wrote, "Twitter no longer has any managers, directors or VPs of color in engineering or product management," adding that he wants "to be a leader in eliminating environments where I am the only African American in engineering leadership."
That's a problem for Twitter's user base, given that it's a popular platform for blacks and Latinos. In fact, a higher percentage of black Internet users rely on Twitter than do white Internet users, at 27 percent to 21 percent, respectively, according to the Pew Research Center.
In an emailed statement, a Twitter spokeswoman said the company is committed to increasing its diversity. "This commitment includes the expansion of our inclusion and diversity programs, diversity recruiting, employee development, and resource group-led initiatives," she wrote. " Beyond just disclosing our workforce representation statistics, we have also publicly disclosed our representation goals for women and underrepresented minorities for 2016, making us the largest tech company to put hard numbers around its diversity commitment."
Those goals include boosting "underrepresented minorities" to 11 percent of staff and women to 35 percent of staff. In 2014, the company said women made up 30 percent of its workers, while blacks comprised only 2 percent of its total employee base.
The biggest slice of Twitter's workforce is white, at 59 percent, followed by Asians at 29 percent. Men make up 70 percent of the overall workforce and 90 percent of the tech-related jobs.
By failing to build a workforce that reflects its user base, Silicon Valley companies -- and Twitter specifically -- have potential blind spots when it comes to engineering tools and services that would better serve their customers, said Mark Luckie, a journalist and former Twitter employee who left the company earlier this year.
"It's really unfortunate, especially as a black person to know that other black people are using this platform to have these diverse and interesting conversations, and those aren't being reflected internally," Luckie said.
Twitter users are taking note, with one user writing, "You have #BlackTwitter damn near running things #onhere, meanwhile no black people in the room for major product decisions @twitter."
The diversity problems at Silicon Valley companies start long before a company grows to the size of Twitter, which has a market value of $19.8 billion, Luckie said. "When Silicon Valley companies start out, it's usually a group of friends or people who know each other."
Later, he added, "They are looking for people who look like them. It makes it harder for a women or minority to come in even if they have the same or better qualifications."
How employees are promoted at Twitter has already become the focus of a lawsuit, with former employee Tina Huang alleging in a proposed class-action earlier this year that the company didn't advertise openings for roles higher up the corporate ladder. Instead, managers allegedly secretly tapped workers to let them know about the openings, a process that she claimed favored men.
Luckie, who left Twitter earlier this year to finish writing a book, said he was acutely aware of the lack of diversity on his team of 150 employees, which included only three black workers. Before working at Twitter, he had worked at The Washington Post, where he said the staff was diverse in race, gender and socioeconomic status.
Leaving the Post to work at Twitter, he said, was like going from "a bowl of Skittles to a bowl of mashed potatoes."