Your reply of "everyone is doing it" definitely could a logical answer to the question of "Why is Musk allowed to be worth half a trillion dollars again?" instead of just a moral justification.
I would agree that Tesla's stock price is as high as it is because investors are betting that there are plenty of other suckers who will be convinced by Musk's unfounded claims.
You are reading the literal meaning right: everyone is doing it.
But you are reading the intent wrong, which is to point out the extent of fraud and deception in boardrooms and markets.