Here's the thing. They don't "occasionally" get beat down. They ALWAYS get beat down. They almost always lose. Additionally, Samoa Joe recently beat the fuck out of two of them in a cage by himself, and a 50-year-old man put the fear of god into like 8 of them WHO ALL HAD WEAPONS AT THE TIME. They look like bitches. Which isn't surprising, because, Devon.
Also, since when was their goal "taking out Sting and Angle" and how did they accomplish it? Because it seems to me that every time they "take out" either of those guys, they come back like two weeks later and single-handedly run off the whole gang.
We don't know what their goals are. All we know is (a) they have a dart board, (b) they have ABSOLUTELY NOTHING BETTER TO DO, and (c) Devon.
You're over exaggerating a bit. Sure, Sting won, but DOC wasn't squashed or buried. It's an ebb & flow for the stable. They can't be invincible and win/dominate every single appearance. First, it becomes predictable and boring if A&E were undefeated. Second, it's the mechanism for their unmaskings. How else would they be unmasked if they were incapable of losing?
Losing a match =/= squash or bury. It's just a loss. If 'losing' ended a wrestler's career, only the Joes, Goldbergs, and Rybacks would have successful careers.
A loss is hardly the end of the world.
Sure the unmaskings have been tepid at best, but it sure as hell beats "Anonymous UnNamed Wrestlers #1, #2, and #3. Granted, Devon, Knox and Gallows are more "Eights" than "Aces" in the Deadman's hand, but there's still 4-5 unmaskings left to deliver.
Their goals spring from their unmaskings. After a moment of vulnerability (Defeat and/or unmasking) they sideline a wrestlers in exchange. Sting and Young have been out for weeks, and Angle is looking to be out for a long while after last week's attack.