To be more fair, the definition of exclusivity is to exclude from a set that which does not meet a specified criteria, and doesn't necessarily have anything at all to do with inclusion criteria itself or number of members in the included subset...

..but then the intended definition was part of my point: can LH tell me what they mean when they ask me if I think their F/HON services are "exclusive"?

It is important to know the definition when one is asked the question, for example, "Do you find the environment in the FCT "exclusive"?
By my definition, the FCT, the Schengen A SEN Lounge, and the airside duty-free shops are all exclusive, but I am not sure that is what LH has in mind with their definition...