The way I see it, the GM is responsible for 5 major things:
1) Drafting - Oversee's the draft and does their best job to ensure they have competent scouts
2) Trading - Assess's the players on the roster and tries to improve the team based on trading
3) Free Agency - Picks up players from free agency that can help the team
4) Cap Management - Signing/Not signing current players, cap management
5) Coaching Management - Selecting the Head Coach for the team
Based on these five points
1) Drafting for Edmonton for been very bad from the second round onwards for a very long time. Sure MacT hasnt been the GM for that long time, but I think he hasnt done enough to change the drafting. Since hes been the GM, nothing beyond the second round has seemed to amount to much. Granted it is still early ...
2) Trading. Honestly I cant be too hard on him when it comes to trading. Hes won some trades, hes lost some trades. Hes still tried to improve the team though and I think his intentions are genuine. Maybe he could be criticized for sticking with his core but I think its very complicated to do and the fact that the Oilers have been so bad, puts him in a bad situation to not get maximum worth. Looking at the Seguin trade and the way Boston is going now, sometimes making a trade doesnt work out. Being patient like Chevy in Winnipeg can pay off I think.
3) Free Agency. Similarly I cant be too hard on him when it comes to Free Agency. I think Fayne and Pouillot were good pick ups. Ference I think was worth the gamble. Nikitin hasnt worked out. But you win and loose some. He hasnt signed a Clarkson or anything to really hurt the team in the long run so thats good. I also think you have to consider that Edmonton is at a major disadvantage when it comes to Free Agency, so I give him a bit of a leeway. That being said I dont think the team in the past has insulated their prospects well, but I think its hard to totally blame him.
4) I think he signed the young players to too big of a contract too early. That being said its nice to have them locked up too. They dont have any really bad contracts on the books that stretch over a long time, so I think it could be better but its not brutal.
5) Like I said early, I feel that this is his biggest mistake. Choosing Eakins without interviewing anyone else has set this teams development back 2 years ... which is beyond awful. When your team hasnt developed properly in 2 years ... its hard to do points 1-4 properly.