My theory is that he hasn't been here long enough to build up a reservoir of positive affect like other high paid veterans (Trouba hitd, Kreider 50 goals, Panarin series winning goals)
We've got fewer fond memories of him and so when there are stretches when he is quiet offensively he becomes the intuitive scapegoat.
To be fair we signed him with the goal of winning a cup over the next 3-4 seasons, so the back end of the contract, while it may be unfortunate, is treated with the same indifference that the final years of the Richards contract were.