@collapsedsquid:
That's part of it but I see radicals echo's Marx's classic "I'm not gonna provide a recipe" comment
Maybe more leftists should provide recipes, not only to guide governments in power but to also provide insurance just in case those governments start making bad decisions-”they didn’t provide fair trials/demolish the nuclear arsenal/etc so we’re no longer responsible for their sins”. The writers of the US Constitution and the Magna Carta certainly felt the need to provide blueprints for their new societies, even if the results failed to live up to the written promises or if they deviated wildly from what was planned.
New recipes would also help people get on board; I can't tell you how many people in my life seem attracted to basic ideas of socialism but ask questions like, “How will movies get made?” or “How will religion work?” These are important questions and I think they should be addressed early on so that people know what they’re signing up for and are eager to fight for it. Marx refused to leave a recipe and now every failed state and genocide perpetrated in the name of Communism are used to smear his name. Jesus left a recipe and he can now be used as moral yardstick to shame his followers who fail to live up to his explicit teachings.