They worked to complete the raids or to get to the chest yea, but they didn't go there with the surety that within that chest or at the end of that raid a Gjallahorn was a guaranteed reward because it wasn't. There was a chance they might get it, just as good or better that they wouldn't. This post has come down to the difference between what you "earn" in an exotic bounty and what you actually "won" from the RNG. You got lucky, you got a Gjallahorn from a chest. However you knew if you completed task X, Y & Z, sometimes W, X, Y & Z you knew you'd end up with Thorn (as in this example). Your kid (if you have one) might get toy "X" for Christmas, there's a chance you may decide not to get it for them and get them something else instead. However if they have an allowance and save their money to buy toy "X" they've earned it. If they get all "A"'s on their report card maybe you promised it to them, and they then get all "A"'s. Guess what, they earned it. That's the difference between earning and getting lucky in THIS example.