A lot of HVCs are business travelers who fly frequently and whose tickets are paid for by their employers/clients. I was in that category myself for several years, flying ~150k BIS miles and earning at least twice that in RDMs. Though I was making good money-- as most traveling professionals do-- those stacks of miles added up to significant value. They provided a very real increase in travel budget over what I was willing to spend out of discretionary income. I enjoyed using points on overseas vacations and last-minute trips that we wouldn't have paid cash for, thinking of it as a dividend paid for all those nights away from home and family.