I think it's important for people (not just people who have personal knowledge of the damage that is done by alcohol abuse but everyone) to know that there are alcoholics who seem to be functioning adults - working, not in legal trouble, paying bills, meeting obligations on the surface but who in reality cannot control their alcohol use. Not every alcoholic starts their day with booze or drinks all day. Many do wait until some time in the evening before they start. And in my personal observations, not all progress to another level of alcoholism. Both my father and stepfather drank at night all night after work all their lives and most definitely were alcoholics but their excessive drinking did not progress.
If the term HFA helps people understand that alcoholism isn't just someone who drinks all day every day but also the man who comes home from work and then isolates himself from his family by drinking quietly and steadily until passing out, then it is not a myth.
IMHO - we need to have people recognize earlier in their drinking life that alcohol abuse is a real problem and to stop long before their lives have become unmanageable. HFA is a term that I think helps people understand that possibility.