That may be true, but I've had good luck asking recruiters for feedback after getting bad news. They usually give some good advice or feedback - over the phone, of course, never in writing. Typically they say something like "You were really strong in X but the hiring manager is looking for someone with more Y." One recruiter told me that the HM had given me the thumbs down saying I was "insufficiently succinct" in my answers! But even there, I had good rapport with the recruiter and he was able to suggest other roles within the company.
If you get feedback that doesn't make much sense, it's likely not the real reason. Just like if a date rejects you, they'll give some silly fake reason why.
Sometimes the reason they give you is just the one that pushed you over the edge. At Amazon being "insufficiently succinct" is a greater err than one might think.
I like that one. I've done interviews where the answer should be at most a summary sentence, and 2-3 supporting points. I know the candidate knows the answer, it's a warmup question! Then what do I get? Word salad. A gigantic run-on sentence where the candidate talks and talks and talks and this, and that, and also, and furthermore... lasting 5 minutes or until I politely interrupt with, "OK let's move on to the next question."
