Blashill, because he's still a relatively unknown commodity. There was noticeable regression with this team towards the end of Babcock's tenure, despite maintaining the playoff streak, so it's no surprise the team continued that trend after he was gone. Blashill has been put in a situation where there was minimal assets added to this team, and the ones that have been added (Larkin, Mantha, Athanasiou) have all appeared to take steps forward in some way, shape, or form. Don't get me wrong, there is still room (and need) for those players to grow, but those guys today are better than they were breaking in. I just don't think we know what Blashill is yet; he came in to run a sinking ship, and unfortunately that's a death sentence of a first NHL gig, especially if it's with a franchise with a history of longstanding success.
It's not like replacing Holland would be interrupting a rebuild plan, because we haven't truly started one yet, mostly because of his stubbornness. The organization feels stale. Yes, the way things were run gave us one of the greatest runs in modern sports history, but like everything else in the world, trends change, rules change, and those that don't adapt and evolve will be the ones who stand to lose the most. We need to stir up the organization from the top down and see if a fresher way of thinking can kickstart another run.