DaasYochid: You are talking apples and oranges here. TheRambam maintains that you should never make money off the Torah- he has harsh words against this. He believes that everyone should have a profession and that Torah should be learned and taught without any reward. The Kesef Mishneh -and subsequent acharonim- maintain that it is very difficult for a talmid chochom to make a living without using his Torah knoweldge for that. Hence, says the Kesef Mishne, one CAN use one’s Torah to earn a living- as teacher, Rav or otherwise. That is the gist of their differences.
However, nowhere does the Kessef Mishneh -or any other Possek- allow people to avoid their obligations under the kessubah, gemoro,mishne…etc. Nowhere does the Bais Yossef condone a system where tens of thousands of people rely upon others for decades.At the absolute limit ,there is a concept of “asoroh batlonim” but not “rivvevos batlonim”. So, your point is misleading because the machlokes of the Rambam and the other rishonim has nothing to do with working and feeding one’s family.