I don't know, maybe because it has the word "deficit" in it. Maybe we should rename it "dollar winnings" or "greenback surpluses". I am pretty sure the trade deficit is driven by the desire of people outside of US to own dollars and dollar denominated assets. As long as US has the strongest military and is seen as the haven for the rich people around the world to park their earnings the trade deficit will always be there, unless capital control is imposed.