It's not the the D is bad, its that the whole team is focused on offense.
While better the past 2-3 games there's still people flying the zone, there's still giving up on plays, there's still lack of rotating when someone changes coverage, ignoring the late trailer and still lack of moving, disrupting or tying up players in the crease. And it's the whole skater group, forwards and defensemen.
This is basic team defense that every team knows how to play, ingrained from the pee wee level. Why are we exempt from it, other than this overriding desire to play pond hockey? Watch a Dallas Stars game, do they do these things? Sure, mistakes end up in the back of the net, this isn't mistakes, this is systemic.
Skinner is average at best, but also costs $3M. Where do we find better at the same price point and also not get taken to the cleaners on cost. And who's to say another goalie wouldn't falter with the same issues. Skinner is failing the most on the rush and on late trailers and that all can improve with a better overall team effort, taking defense seriously, and being responsible, not cheating for offense and in a giant hurry to get to the other side of the ice.