Because:

- Musk still has an axe to grind to justify his claim that Twitter was catastrophically mismanaged.

- He has a history of making very false statements about Twitter, including most recently that it’s the world’s biggest driver of ad traffic. That harms his credibility.

- He has been CEO for what, two weeks? And he’s suddenly discovered all this bloat stuff that others missed? Again that seems unlikely.

- This is a claim that on the face of it doesn’t pass muster, given what’s known about Twitter’s engineering approach. That should introduce more scepticism.