That doesn't matter, because people can independently look at the design of the crypto. Your point about authentic in this context is meaningless.
> Integrity of the message doesn't matter - if you see a message and it makes sense to you, then that is all that is necessary.
That's exactly why you sign a message, to judge the veracity of the contents according to a trust anchor.
> If it's something stupid, what does it matter that it's signed?
You are fundamentally misunderstanding the purpose of signing messages. You don't sign to check stupidity, but to assert that important yet unsigned messages can be repudiated from the party believed to be the origin.
Another way to illustrate this - in the Bitcoin world it is best to assume all messages are spoofed and never trust signatures.
That's WHY you sign messages. It isn't a reason not to sign messages. You are confusing authentication of origin with identity of sender.
Right, you use your brain to check for stupidity, and once that check is complete, identity, authenticity and consistency of the message does not matter.
Bitcoin is a trust-less protocol, you cannot and should not trust any node, miner, developer, any online or offline post. Trust is not a thing in the Bitcoin world, and the tradition of not signing communications is generally rooted in this concept.
Please feel free not to believe me-- you shouldn't, I could be shilling for Craig Wright (ironically the one person who has proven that he isn't Satoshi) ....
At this point Satoshi is a principle and a philosophy and bitcoin needs to survive without him.
The person who used that alias would be offended at the idea that the direction of bitcoin should be determined by him.
In this case you can get all sorts of sybil attacks to manipulate consensus by sheer numbers, including fake news and so forth.
Imagine HN without reputations or limits on spoof accounts.
Integrity of the message doesn't matter - if you see a message and it makes sense to you, then that is all that is necessary. You can agree or post a response to argue a point. If it's something stupid, what does it matter that it's signed? And if it is from "Satoshi Nakomoto", how naive would you be to actually trust that?
Another way to illustrate this - in the Bitcoin world it is best to assume all messages are spoofed and never trust signatures. Even a signed message can be fake, it could be a lie or it could be written under duress. The only solution is to not trust signatures.