Twitter is one of the Silicon Valley companies most criticized for a lack of diversity, and its latest hire isn't helping that image. The company recently announced that Jeffrey Siminoff will replace Janet Van Huysse as vice president of diversity and inclusion. Siminoff, who is white and male, was previously Apple's head of diversity and is a strong promoter of gay, lesbian, bisexual and transgender rights. However, the move was criticized by diversity proponents like Mark S. Luckie, who didn't take issue with Siminoff himself, but rather the decision. "Not saying a white guy can't be head of diversity, but for a company that hires a majority white guys [sic] it sends the wrong message," he tweeted.