IMO Kreider is part of the solution and not part of the problem.
The biggest problems on this team in no particular order are Igor, the defense not named Fox, Gus, or Schneider, the lack of center depth, our 1C playing like a 2C/powerplay specialist, and Barclay Goodrow's contract.
Kreider gives us something few players in the league do, is still really good at it, and it's also a skill that tends to age better than if he was still playing the speed game.
I don't think any of this is wrong, but thats exactly why he'd be the easiest to move.
What I don't like is that his game is becoming more uni dimensional. Now alot of that may be because of who he's playing with but that isn't really an excuse either, he can be a factor in so many areas but he just chooses not to (and I know it's a choice, because there are games where he decides to do these things and is very effective.)
I get the apprehension as he scores goals which is hard to do in this league and he's scored a bunch in the the playoffs which is even harder to do, but that isn't really going to matter if the rest of the team doesn't carry their weight.
Plus if you look at the other guys -
Trouba probably could be moved, but I'm not sure that they would do it.
Panarin would be a tough move and he's got full no trade
Zibanejad can't be moved.
Fox shouldn't be moved
Goodrow should be fired into the sun, but honestly that probably isn't enough.