Wow, is he still bitter about the new show? You'd think having a recurring role in it would have appeased him. It must really rankle that he couldn't get his vision through and that the new show is incredibly good.
He's the one who started pitching a revival and got people interested, then the execs picked someone else to do it with an entirely different vision. It was a nice concession to put him on the show in a fairly high-profile role, but he wanted a lot more.