An example of intellectuals’ need to make everything more complicated and difficult than it has to be is the unending debate over the meaning and validity of the Marxian claim that the economy is the relative foundation of society, that production relations (which presuppose given levels of “productive forces,” i.e., technology, scientific knowledge, etc.) are ultimately the most important kind of social relations. One would have thought this claim to be commonsensical, but apparently it isn’t. Its basic meaning and truth are revealed in the single consideration that the institutions and institutional actors with the greatest access to resources are going to have the greatest influence over society. Fewer resources, less influence. Institutions directly involved in the production and accumulation of resources—of money, capital, technology—are naturally going to have the most direct access to these resources, i.e., the greatest control over them. The people who control these institutions, then, are going to have more power than other people, and they will seek to make other institutions throughout society “compatible” with their power or subservient to it. Which means making them compatible with the form of organizing relations of production in that society that has the most control over the most resources. In other words, the “dominant mode of production.” In non-prehistoric societies, the class structure and implicit class struggle, which are defined by the relations between antagonistic positions in the mode of production, will therefore be central to social dynamics. The more exploitation* of the producing class(es), the more power there will be in the hands of the exploiting class(es), i.e., those who occupy the dominant positions in the dominant mode of production. (Their dominant position is a function of their control over the resources necessary to force others to produce for them.) The exploiters will try to increase exploitation as the exploited try to diminish it. The vicissitudes of this struggle will go far towards explaining other political and cultural phenomena, because the struggle—which is integrally connected to the evolution of the relations of production, of the class structure, of economic institutions, as well as the closely related evolution of the forces of production—largely determines who has how many and what kinds of resources when, what sorts of institutions and values the people with resources will promote, etc.
It is true that in other senses, the biological division between the sexes can be called the “foundation” of society. But not if you’re talking about the specific forms that particular societies take. Biological facts do not explain that (do not explain differences between societies); economic institutions—in addition to environmental circumstances and the nature of existing productive forces—do, at least to a very rough approximation. (One also has to keep in mind Raymond Williams’s concept of the “residual,” the cultural, political, and economic residues of previous systems, as well as the sheer infinite complexity of a society’s economic institutions, including the coexistence and even interpenetration of different modes of production.)
To take a non-capitalist example, in the Middle Ages the Church owned vast tracts of land and had immense wealth. As a consequence, it had enormous influence over the whole society. What could be more commonsensical? The Church’s and the feudal aristocracy’s ability to force others to work for them and/or to appropriate their surplus product allowed them to impose their institutions, norms, and values on the rest of society. Their control over the means of violence was necessary, of course, to their economic power—and was in turn the result of prior economic facts, prior accumulation of resources by certain people and institutions, etc.
In short, the core of historical materialism is mind-numbingly obvious and should never have been controversial at all (and surely wouldn't have been if it didn't implicitly challenge the legitimacy of dominant classes). But in order to be a successful intellectual it's important, generally, not to be a clear and honest thinker. Instead, you're supposed to produce mountains of verbiage that obfuscate, legitimize, distract, “problematize,” and indoctrinate. Why? Because this serves to uphold the power of the dominant class. (But even leftist intellectuals are frequently guilty of muddled thinking and obfuscation, because they too have been indoctrinated, to some extent, with the proper institutional norms.)
*Uh-oh, a controversial word! If you're skeptical of the Marxist theory of exploitation, then just think of it this way: the dominant class "exploits" the relative lack of freedom and power of the subordinate classes, by compelling them to work and appropriating much of the product.