Probably he is a friend or someone wanted to be recognize even though he isnt active.
Are you saying leaving an inactive member's name there as a moderator is a kind of compensation for him from owners of this forum? I do not think that is the case. What you just said now can be done in a proper manner if at all by getting those who have helped this forum one way or the other into a Hall of Fame for this forum. Just open a thread and pack them all in there by mentioning and branding them.