Lol Marc Staal was still really, really, bad when he came back from surgery. From Dec 8 (when he returned) to the end of the regular season he was at the bottom of the list amongst regulars in almost every major statistical category (including TOI, so his minutes being cut are not a new development.) I know Uncle Larry tired to spin his GA numbers by comparing him to a shit load of players who had 100+ more minutes played than he did, but even that ended up leveling out as time went on.
Most of us who have wanted him gone have been told by the pro-staal'ers that he would be fine if he was just used in a 3rd pair role because he is still "rock solid" defensively. He was used in that role this year and he was still a major liability.
He was the worst D in the league when not paired with DeAngelo this year, its not a coincidence that he looked like a drunk beer leaguer during the play ins since DeAngelo couldn't carry him around on one leg. This is who he is and has been.
He can't be sheltered in any role and needs to go. He only played because the coaches and FO love him, Smith was a better option and played forward for almost the whole season because of it. Even if they didn't have a replacement in Hartford, they could have easily picked up a player off the scrap heap who would have outperformed Staal.