Or perhaps "owner" would do. It might not be what you would like but they own the place so it's their right to do what they like with it.
Of course when they ruin it, it just opens up competition for more enlightened compaies so it's not all bad,
Instead, activist investors own a small, but large enough chunk, advocate for what they want and rely on other investors being passive (e.g. because a lot of the company is owned by tiny slivers of much larger portfolios) even if what they're advocating isn't in other investors' interests.