I don't believe he gets any royalties from BOOH now. He made a settlement, and says he no longer gets anything for it. I think he's just pleased when it rushes up the charts because it's his work and he takes an understandable pleasure in it being continually recognised
As Andy says, maintaining and increasing his visibility to the general music listening public is a great thing. Whatever the reasons for the many surges in success it keeps enjoying, it's a continuing tribute to Meat and Jim and an outstanding legendary album.