Is revised atlas so unprofitable? (2,1,4)

I believe the answer is:
'unprofitable?' is the definition.
Both the answer and definition are adjectives. Perhaps you can see a link between them that I don't see?
'is revised atlas so' is the wordplay.
'is revised' is an anagram indicator.
'atlas'+'so'='atlasso'
'atlasso' anagrammed gives 'AT A LOSS'.
Can you help me to learn more?
(Other definitions for at a loss that I've seen before include "(Running) in deficit", "Uncertain what to do - bewildered", "how a bankrupt business was run", "Totally bewildered", "Unable to understand - no profit in it".)
I've seen this clue in Sydney Morning Herald.