Square says its employees might get too rich
washingtonpost.com
washingtonpost.com
And Alibaba's F-1: "In addition, we have a number of employees, including many members of management, whose equity ownership in our company could give them a substantial amount of personal wealth following our initial public offering. As a result, it may be difficult for us to continue to retain and motivate these employees, and this wealth could affect their decisions about whether or not they continue to remain with us. If we are unable to motivate or retain these employees, our business may be severely disrupted and our prospects could suffer." https://www.sec.gov/Archives/edgar/data/1577552/000119312514...
Etc.