There is a method to Musk's "madness." By being so public about his sociopathic behavior, he has garnered a huge amount of celebrity (as autocratic sociopaths often do).

The SEC would make Tesla's board force him out for his clear, multiple legal violations if it were not for the their fear of public backlash. No the SEC is not beholden to public opinion, but the people who make the SEC decisions have careers and a desire not to be hounded and/or blacklisted.