Another reason is when a family dominated publicly traded company runs out of family members interested in running the business.
Case in point: Gerber Products Company, which was #348 on the list in 1955 and #307 in 1994 at the time when the shareholders of the company sold their shares to Swiss pharmaceutical firm Sandoz (now Novartis).
Frank Gerber founded the company, and his son Dan made Gerber a household name nationwide, with trusted baby food products and one of the most notable trademarks in American commerce. Dan had four daughters and one son. The daughters all married Ivy League types who were nice guys (one of them was a very successful real estate investor and two others had desk jobs within the company) but with little desire or aptitude for running a business which had expanded to places like continental Europe and South Africa. The son spent his adulthood driving race cars and writing poetry; he tried teaching high school students but didn’t make it through his first semester.
Dan died in 1974, and by 1990, with no capable family members left to receive the torch, the Gerber heirs and their advisors decided that the best course of action was to sell the company as a going business. It took them a few years (they openly were courting Anderson-Clayton, and quietly were talking to Campbell Soup), and ended up with Sandoz, which became Novartis. Novartis got out of the baby food business when they sold Gerber to Nestle, its major international competitor.
My father was a career Gerber employee (1948-1984), and I am a Gerber baby, having grown up in Fremont, Michigan, Gerber’s HQ.
Third generation business failure seems to be the norm out here in Flyoverville.
The founders start a business to produce goods or services they are interested in; "grandpa" (or "grandma") is respected by the employees.
The founders' offspring take over the business and try to increase assets; the employees are ambivalent about the "kids."
The founders' grandchildren take over and either spend the thing into the ground or liquidate the assets so they can live it up; the employees think the "grandkids" are out-of-touch a$$holes.