I think the criticism "he tries to beat guys by himself" is nonsense. I don't think he does it too much and even if he did it more, lots of players in the NHL do that.
I think the criticism that he's soft or won't go to the danger areas is also false. He is very willing to get into a battle or get his nose dirty, he goes in the corners, he gets to pucks first even if he knows he's going to be hit, he leans on guys, he draws people to him and takes hits to make plays. He plays with courage.
What I think is fair to say (and I haven't actually heard anyone say this), is that he lacks a 'second effort' in his board battles. He will fly in on a loose puck or to pressure or engage in a puck battle, but if he doesn't come up with the puck on that first try, he's done. As Andy Brickley is fond of saying, "this is a second effort league" and almost everyone, from stars to plumbers, give that second effort. The greats give a third effort. They get denied, they keep coming, over and over.
I think that's what the Bruins have been waiting to see develop in this kid. The talent is there.