Political democracy also mandates legal non-transferability for voting rights. Would you allow people to sell or transfer their voting rights?
People prefer democratic firms: https://www.cambridge.org/core/journals/american-political-science-review/article/what-do-americans-want-from-private-government-experimental-evidence-demonstrates-that-americans-want-workplace-democracy/D9C1DBB6F95D9EEA35A34ABF016511F4
A mandate doesn't restrict any non-institutionally-described action as labor is de facto non-transferable. It only prevents fraudulently treating de facto responsible persons as legal non-responsible things.
Are we free when we can sell our freedom or when we can't even if we want to?