They did, he was replaced by Nylander on the top unit.
But it's really dumb that Babcock pulls the top unit off the ice after 40-50 seconds. Then the second unit plays 40-50 seconds, does nothing, and the first unit but with two D comes on for a garbage final 20-ish seconds.
Just leave the stacked unit on for 1:30 like other coaches do.
They don't leave them out for 1:30 when they struggle to generate much of anything especially something such as zone entry.
The issue is the PP is too much of the Marner show running an ISO with him and his decisions with the puck have not been good at all for some time now not to mention way too slow in moving the puck.
When the PP was successful Marner moved the puck quickly. The puck moved around and when it got to Marner on the half wall he attacked a transitioning PK before they were set that gave him 3 options. It's one deadly set up when puck movement sets up Marner to make plays rather than giving him the puck like a guard in Basketball ISO play with the others sitting still waiting for him to do something.
Once again even for the PP it comes down to compete leading your skill rather than your skill leading your compete. If not everybody is on board with this simple tactic your skill level doesn't matter how talented it is will take you only as far as your goaltender can take you in the long run...
The issue isn't system, isn't Babcock... It's a wakeup call for the players to put there big boy pants on and start to make COMPETE the bread and butter of there game in bringing there skill level and not the other way around.
How do you beat high end talent? You outwork it
How do you beat high end talent that outworks you? With a hope and a prayer your goalie is the 1st, 2nd and 3rd star of the game.