That's not how organizations work. You can't just slowly take out the "bad" people and replace them with "good" people and expect that to fix anything. It's the wrong mental model.
Organizations are sticky. They get stuck in a rut, basically. The slow trickle of new people gets indoctrinated into the Company Way (or else selectively ejected), and the people that are able to leave often use it as a lesson of what not to do.
If you've ever read the details of that crash... I can think of no better example of where "corporate death penalty" should have kicked in. Instead Alaska has bought up multiple carriers and increased their footprint, all while continuing to engage in shenanigans.