Duchene has played with almost everyone under the sun, and the reason for this is because he finds it hard to develop chemistry with guys, and goes into slumps, and gets his linemates changed.
Nine years into his pro career and he's still having these issues. I think it's fair to say at this point, the cause of these slumps lie more on Duchene's shoulder's than his linemates. You could fill up a whole roster almost with the amount of guys Dutchy couldn't gel with.
It's not talent, and it's not how much he cares about the Avs winning. He's filled to the brim in both categories. He just overthinks everything on the ice, and puts too much pressure on himself off the ice.
The reason I think he gets talked about so much is that he looks so dominant when he's playing confident hockey. When he's playing with a lack of confidence, and overthinking all the plays, he's noticeably a step behind what he's shown capable of, and it can be a bit frustrating to watch. Like right now, there just isn't something right about his game, and how he executes plays with the puck.
He's capable of being a fairly dominant PPG player, he just can't find that level of consistency. That's why to me, he makes a better winger, where the expectations are lower. Hopefully the Avs can have MacK as that dominant near PPG top center, and either Jost or Mikko as the two way presence you need in the #2 spot.
Dutchy is then free to be streaky, and end up with 25-30 goals and 60 points, and we'll be happy about it, rather than overly frustrated with it. As of now, the team is in a transition phases, and he's still relied upon more heavily than he should be.
He really should be that Jeff Carter/Marion Gaborik kind of guy where you can win without him scoring, but he can get hot and win you games, and come through in the playoffs when the opposition focuses on guys like Landy and Mack. To do that though, they have to build the team properly around him, and get them playing sound hockey.