Then there is the tankie Left, which also started with good intentions but seem to have confuse the recipe-book of slogans and the Party über alles discipline invented in the late 19th century and early 20th century by middle class intellectuals to inspired the near-illiterate masses of the time to create an utopian leftwing world (which didn’t work) with the actual thinking Principles and Intentions from which the rules were made.

The “tankies” are absolutely not utopian. There was a great big schism about this very question more than a century ago, with Marxists roundly rejecting the utopianism of the libertarian socialists (Anarchists). Socialism: Utopian and Scientific by Engels is a good starting point.