Why label them at all? It's just a word with no substance--we all have different definitions, and none of them are "right." Thoreau was considered a loser; so was Einstein--were they losers?
By the very nature of the word, "loser" means that you've lost something--and that you've caused that loss (think about a "lose-er" vs. a "lose-ee"--just like employer/employee). So if you go about life causing your own losses, whether it's prosperity, relationships, or whatever, maybe you are, objectively, a loser. I don't know.. just a thought.