You must also keep in mind the strong cultural divide in Mexico between the Amerindian, rural south and the industrialized north. There are several fissures in Mexican society that go far beyond the feudal system you describe (most of which was abolished by the revolution). Mexico had a revolution, land reform, and a welfare state, but none of these can compensate for certain cultural and political practices that retard further development.
Remember that, for all of its problems, Mexico is a "middle income" country. Be thankful you don't live next to Niger...