I don't know that any of those guys is good. But Lundestrom is a big part of it. This season, his xGA/60 on the PK is second worst to Vatrano. Over the last three seasons, there are 145 players who have spent more than 200 minutes on the PK. Lundestrom is 5th worst in xGA/60 (2nd worst in actual GA/60). Now, there are a lot of Ducks high on that list, which indicates that there's plenty of blame to go around (including to coaches), but he's above (below?) them all. I'm not sure why people go out of their way to defend him.
At best, the argument is that Lundestrom doesn't matter because he's just a 4th liner. And that's mostly true, particularly for a team that's still as bad as the Ducks. But it would be nice to have an actually good 4th line center who can win faceoffs and PK well.