My first comment said that sensible economic policies are not politically feasible. I certainly don't predict that sensible policies are going to be adopted or sensible systems created through our current political institutions. Meanwhile, Marxism failed because the theory was wrong, not because it was politically unfeasible. It is possible for a system to never happen even if the theory behind it isn't wrong—Nash equilibria can remain and not spontaneously turn into Pareto optima even when there exists a Nash equilibrium that is a Pareto improvement over the current equilibrium.
There haven't been that many large scale attempts to revolutionize society in history and some have worked just the way some people expected without hindsight. So it is in fact possible to predict the outcomes of a large scale system through causal reasoning and to have a reasonable idea of their desirability.
> There haven't been that many large scale attempts to revolutionize society in history and some have worked just the way some people expected without hindsight.
Which ones worked "just the way some people expected without hindsight"?
There haven't been that many large scale attempts to revolutionize society in history and some have worked just the way some people expected without hindsight. So it is in fact possible to predict the outcomes of a large scale system through causal reasoning and to have a reasonable idea of their desirability.