Companies flip back and forth from publicly traded to privately held status. In addition to the usual explanations (cashing out, currency for acquisitions, etc.), I think I now understand one more: the grass is always greener. Public company managers look fondly at avoiding quarterly targets and disclosure. Private company managers dream about being widely held and losing activist shareholder/directors.
But the bias is likely towards the second - the sinecure of a (widely-held) public company is very attractive to management.