A good GM should see things differently than fans (who are inherently underinformed amateurs) and so their moves should feel a bit mysterious to us. So to the question of Z being "snakebit" and having inexplicable bad luck... I say the guy was just making bad moves. Moves that may have seemed smart to us fans too!...and so we want to let Z off the hook...but the problem is we aren't brilliant GMs ourselves, so we're committing a circular fallacy by thinking this way. Our best way of evaluating a GM who's had 7 years on the job is by results. Not by trying to follow along and grade every individual "process" decision as if we know what a good GM process looks like.
Plus, organization and culture really do matter even for something seemingly more objective like sports performance. And if there's one thing Baker has irrefutably established, it's that Z was a failure at these aspects of the job. Notice how nobody has ever spoken up in Z's defense in any of the Baker pieces. The silence speaks volumes.