He's trying to find a scapegoat to blame for destroying the company, and he seems to think he's found it in the advertisers that are withdrawing their money.
I heard David Samson (former president of the Miami Marlins) suggest that he wants the advertisers to all bail so that he can entice his sycophants to boycott the companies who pulled their ad revenue.
He suggested that if you have the type of f-you money to waste that Musk does, then it's simply an ego move. He's not going to succeed with XTwitter so he might as well let it burn, and scorch as many people as he can in the hopes of getting petty revenge on those who crossed him.