Neither can Kronwall at this point, but we play him there.
That is true. IMO, Dekeyser has been average while playing top 4 minutes. I don't see how increasing his ice time by 3-5 minutes against better competition is going to help his play improve. Who knows, maybe he jumps in and does better than Kronwall is doing. Anything that helps this team is a welcome sight of course.
Kronwall plays on the top pairing because someone has too. I'd have no problem bumping him down a pair, but I don't see anyone on the team who can replace his 24-25 minutes a night. Mike Green doesn't even play that much ice time, and his numbers are basically the same as Kronwall (not sure about advanced stats).
So while everyone may hate Kronwall's play right now, he still plays the most IT out of anyone on our team by a decent margin. He's 35,plays the most ice time, and is declining. Why doesn't Blashill (or even Babs when he was coaching) reduce his minutes and bump him down a pair. Maybe its because they didn't believe anyone else could step up properly and do the job better than Kronwall. What does that say about the other D on this team if they can't beat out a 35 year old, declining D for top pairing minutes?
I can easily see Kronwall doing much better if he was playing Dekeyser's minutes and situations. I don't think Dekeyser would do better increasing his ice time against better competition.