We had a similar situation - with a very important member.
Eventually we set up a specific rank with the same title as an existing rank, and allocated it to that member - no progression, no ranking gamification.
Best thing I can suggest would be to set the No Gamification rank to be role-based,
With badges, you can then set a role to "view badges".
Hopefully then if you have any other old-schoolers for whom gamification is a deal breaker, then you can just assign this role in the future.