Mr. Musk apparently supports the free utterance of views anathema to some of the more left leaning elements of society, and as such they believe both Musk and any platform he owns should be ostracised and those that disagree with this stance be denied any large social platform.
Avforums political discussion sections are a UK based example of how anti free speech platforms operate, any dissenters from a hard left stance are bullied, mocked, cajoled and if that fails, banned.
That forum was quite politically balanced until the break up of Digital Spy saw a hard left infiltration from there, who slowly drove out any contrary view points until it effectively became another enforced leftist only meeting hall.
Musk appears to want to address the claimed imbalance in moderation on Twitter, and those used to using strong arm, (and moderation supported), tactics against those of different political persuasion are having hissy fits that a balance may be about to be returned under his ownership.