To take an example at the far end of the spectrum: in 1989 WPP (the world's largest owner of advertising agencies) bought The Ogilvy Group (a very large ad agency) for $864 million ($1.7 billion in today's dollars.) Ogilvy was nothing but people...there was no other value (except, maybe, the brand, but that's debatable.) At the time people criticized the deal, saying "all of their assets go down the elevator every night." But it turned out to be a great acquisition for WPP.

While the founders and first few employees may leave after an acquisition, preferring to work for themselves, everyone after that is an employee and, as long as they are managed and compensated well, will generally not care so much who the company's owner is.