Ownership had nothing to do with Bowden and Riggleman leaving, in fact, I'm certain the owners are the only reason these guys were even employed by the Nats in the first place. Bowden and Riggleman made their own beds, particularly Riggleman who is just an idiot.
Kasten is something else entirely though and more comparable with what you're describing. I think it's safe to assume that Kasten and the Lerner's had different agendas. Though, it's not likely I'll ever shed a tear now that Kasten is gone.
Your second statement contradicts your first statement.
Losing three guys in upper management in three separate ugly manners is not a good thing no matter how you spin it.