Lets look at the teams who have moved him-
Chicago (he started here and was moved mid season, a year too late as they could have gotten a bundle for him coming off of his 60 point season) who sucked.
Philly (who signed him to a 1 year deal at decent money) who sucked
Washington (on a similar deal to what he has here) who also sucked.
Teams don't generally prioritize bottom pairing defensemen, especially ones who are really bad. If we were expecting him to step into the top 4 you'd have a point but that isn't going to be his role. Bottoms pairs around the league are littered with guys who are worse than he is, including the team that just won the whole thing and the team that they beat (who had a worse player in their top 4.)