The first two games in Vancouver were pretty tough for him. That said he has been getting better every game, he has been getting the puck more, making plays with the puck more and seems more sure of himself in the defensive zone. He has the ability to play in the NHL and as long as his game keeps growing, there is absolutely no reason for him not to be in the NHL.
You mention him being sheltered and while Ottawa has been on a road trip. His most common opponents vs Edm were the top two lines and d pairings. vs MTL it the 2nd and 3rd line as well as the 2nd and 3rd pairing.
I really don't understand your angle here. Sure he has parts of his game that could use improvement but as long as he shows he can get better while playing in the NHL, why not have him there?