Without some idea of what we're going to build afterwards, we're going to end up beheading more and more, even innocent people, just like the Reign of Terror. And then we'll (by default) create another state with the same problems because it's all most people will imagine.

Fists are for smashing things, spines are for supporting things. What would you want after the guillotine? This isn't a gotcha, I'm seriously asking which new social order would be more resilient. Do you think Marxism-Leninism worked out well?