Here's the way I see it.
There's no question we have the skill and talent (at least up front). But the other intangible needed to make a deep run is that burning desire to want to win and run through the endboards to get there. These guys just don't have that intangible - at least not right now.
So the question Dubas needs to figure out is - who has the character and willingness to lay it all on the line and perhaps get bloodied to do so? He's obviously betting the farm that they will learn and get there eventually. However, it's not hard to see that some of these guys don't have this character trait. These are the guys need to go and you bring in guys willing to lay it out there.
For me, the first guy to go should be Nylander. I love watching him play, but I just don't see him going above and beyond what's needed.