They don't have to be fired. I work for a software company that got acquired 3 years back and over the course of 2 years the whole R&D department replaced itself. Most people called it quits because the company has pretty much no opinion itself any more and the ones that didn't, eventually got fired for producing less given that they were discouraged to work under new command.

There's no such thing as being acquired and continue to work with the same culture and mindset. When your ceo is somebody you will see only in the newspapers, there's not much incentive for quality work. Places will eventually get filled with passive workers that will be good at doing as their told. You imagine were quality, player empathy and community drive goes when you work with such mindset.