Huge swaths of ideal Tesla buyers are turned off by his behavior. He has polarized the brand.
I can't deny his genius or all he has achieved. I own a Tesla I bought after the X purchase. It's the best car I've ever owned by a wide margin, and notably, the Model Y is the best-selling car on earth.
That said, I am the CEO of a company, and I have no personal social media presence; I am a registered independent, and I work to be the reason clients choose us, or at least not be the reason they don't. That's why so many CEOs are bland.
When you run any company the goal is to let the products and the people behind it shine. This is fundamentally opposed to Musk's rockstar me me me approach. Granted, his approach was great initially, but to cross the chasm, Tesla needs to appeal to everyone.