The facepalm isn't about removing defensive responsibility to Galchenyuk, it's the fact that MT keeps referencing to DD as a great two-way, skilled defensively centre when that is not at all the case.
I don't think he said that...
Clearly, DD's not the one impeding Galchenyuk's ascension...it's Plekanec
Whether or not Galchenyuk is playing center 12 mins a night with Eller/Andrighetto/Carr
or
Whether or not Galchenyuk is playing cente 16-18 mins a night (like Desharnais) with Fleischmann/Weise/Eller
It doesn't really matter.
The question at hand is that Therrien refuses to use Galchenyuk at center with Pacioretty/Gallagher because he feels he's not responsibile enough defensively, while he'll continue to put up with Plekanec's complete ineptness offensively, because he's perceived as being a top defensive center.
Those of you looking at DD as Galchenyuk's biggest impedement...aren't looking in the right direction.