Well, for one, this sounds just like yet another Elon-hater's comment. In _most_ cases, Elon's businesses are fairly successful, so a sarcastic "Elon's latest genius innovation" doesn't belong here.
For second, how do you know the idea came directly from Elon? It could easily be the result of a brainstorming session led by a product team.
Elon is not writing Twitter's code. He is not a Software Engineer at Twitter. Even if the idea came from him, why is he being attacked for a bad deployment?
And lastly, why do people think that the change is bad? There are plenty of web sites that do not allow you to view their content without creating an account first. Is Twitter not allowed to experiment? Why not? I would appreciate hearing well-thought-out arguments that explain the potential negative impact on the business.
Because it's quite literally one of the things he's responsible for at Twitter, by his own choice and description of his role (https://twitter.com/elonmusk/status/1656748197308674048).