The premise of historians not liking assassination of Julius Caesar is that Parenti spends most of it debunking the traditional claims of Caesar being assassinated for being a tyrant and instead shows he was assassinated for doing populist reforms that pissed off the landlords and ruling class (I think mainly for societal stability not because he was pro worker or anything)

The traditional historical view is almost entirely informed by the landlords and ruling class pov, and since the historians are drenched in liberalism they never really went out of their way to question the ruling class.

It’s been a while ( years) since I went over it though so this might be off a bit