I do really like they way von Mises broke down the human action and it is related studies. It is different to study what person should strive for (ethics), why people strive for something (psychology) and how people can attain the goals they have chosen (economics).
The understanding that economics is not science that can and should not do value judgement is a great contribution. Scholars are free to offer they ideas about ethics, but it is a different discipline.
On this background you should look with his criticism against socialism. He doesn't say that goals of socialism are bad. He just points out that tools and processes advocated cannot achieve the stated goals. And he had fairly great concrete criticism about socialism in his 1920 book "Socialism: An Economic and Sociological Analysis". This predated the great Soviet Union and Chinese socialism experiments, which haven't proved him wrong.
Von Mises was not so advocating about creating theories that don't stand the test of real world. His aim was always to understand real world phenomenon. His rejection was about using tools that don't work with humans. Physics and chemistry are governed by constants like gravity, electromagnerical force, weak and strong nuclear forces that allow you to use advanced mathematics to study them and isolate these constants. Economics do have laws as strong as laws of motion, but you cannot find these the same way as human action is variable.
I do get same feeling about Richard Feynman. For him it seems that you needed to have a mental model first about a problem, before trying to model it with mathematics. [1]
You cannot progress without insight and you cannot have insight without interaction with real world. Theories only have value if they can affect actions in the real world. And there is a lot of ways outside of p-values how to allow that feedback from the real world to affect you. And this is something I feel that all of those people intuitively understood. :)
[1] https://thinkjarcollective.com/articles/richard-feynman-spin...