John Moore is certainly far from perfect, especially in his own end, but being the 7th+ defenseman isn't an easy job as well as simultaneously being a thankless job. That said, Moore looked good against Philly and I think people are generally way too harsh on him. Seems like its always the same group of contrarians who despise him because they dislike Sweeney, his philosophy or the contract given to John Moore. I don’t imagine it's an easy task, going from long stretches of being dormant to suddenly having to go into the lineup and be expected to be solid, that is.
His contract is far from an anchor and I suspect he could be moved with relative ease (sweetener maybe), especially looking around the league and seeing some of the defensemen that are seeing regular TOI around the league. However, I truly don't think Sweeney has been looking to move him with haste or at all. His contract isn't hurting the Bruins and they have plenty of cap space to add players or make roster maneuvers with ease, as seen recently with this team.
TL
R - John Moore isn't perfect, but he's mobile, keeps up with the play and has a really good shot when he's in position to use it. He's a solid, serviceable bottom-pair defender who has the thankless job of coming in and out of the lineup with little time to prepare or get into his groove, like any other defender who's usually an extra. Not perfect, but the Bruins can do far worse than John Moore as their spare defenseman, even at his cap hit and term.