There's a decent amount of blame to go around. Obviously Sullivan (and maybe more so Reirden) takes the brunt of it but it's not pretend the players aren't playing their role in this dumpster fire. At the end of the day, Sullivan can't be the one shooting and skating and making good passes, so there is quite a bit on the players as well.
One interesting thought that hasn't really been thoroughly discussed (yet, lol) is Dubas. While he did a great job turning this roster over and providing them a lot of decent players that better complement the system but at this point, it can be clearly seen that something isn't right and we may be in need of a new player or two. There are plenty of players out there struggling at the moment - Anderson, Domi, Rakell, Burakovsky, Athansiou, Silfverberg, Pageau...I mean, if you go down the list there's a number of notable names in a similar position as Rakell. To the point where I am shocked there hasn't been a swap between two teams at one point.
We have POJ as well who may be a good trade chip to get a new face in the forward group. I don't think we are getting rid of Graves and besides him, I've very much okay with the defense. I think we need to try to get a different skill set in the forward group to hopefully make something click. A new Hornqvist is obviously the answer but that can be said for about 31 other teams as well.
In previous soap box speeches about the trials and tribulations of the Sullivan era, one of my primary criticisms was - I get that he will eventually make a change but I wish he wouldn't crash the f***ing plane into the dirt and kill all of the passengers before he decides to pull up. He rides bad decisions into the ground. I hope Dubas doesn't let this current roster skid into the ground into a state of irrelevance before they say "Oh, let's do this now! We need to do something!". That need manifested itself about 3 weeks ago. So while I get he won't be canned, the clock is ticking for Dubas as well if he wants to avoid shouldering a larger portion of the blame than what he needs to.