Marx vs. Weber: Goals of Capitalism

Your question is a very compelling one and I have been wondering a lot too about comparisons and contrasts between Marx and Weber's ideas on capitalism. I have come to a conclusion, so far, that is rather close to, yet slightly different from yours.

It is to be kept in mind as starting point that Weber does identify the shift from Wertrat to Zweckrat as the historical transformation leading to modern, secularized and profit-oriented market capitalism - the age of the faceless bureaucrat - from a socioeconomic form which was already somewhat capitalist, yet driven, as you say too, by different goals. Therefore, Weber actually describes all those "different 'eras' of capitalism" through a historical analysis which understands culture and values (here fundamentally embodied within religion) as driving historical change. This is what seems to me the trait diverging the most from the Marxist analysis based on historical materialism, rather than the eras and goals of capitalism that they are describing.

So, perhaps it is the case that the quote from the summary refers to a specific era of capitalism which precurs the modern one, but that it is not to say that Marx and Weber talk only about different eras of capitalism. The Weberian description of capitalism's goal captured by the quote can be reconciled with that of Marx as it is describing the goals of a wertrat era of capitalism, but Weber does also elsewhere pictures the era of capitalism in which we are currently trapped, and which Marx describes as well, where "the pursuit of wealth (Erwerbsstreben), divested of its metaphysical significance, today tends to be associated with purely elemental passions" (PE, p. 122) as consequence of the historically revolutionary invention of enterpreneurship.

I will lastly argue that this very last point may be the strongest connection between Weberian and Marxist theories of capitalism, at least at their explanatory level. In fact, while they approach its causality with starkly different means (respectively, idealism and materialism), they do seem to agree, among other elements, with the centrality of class structure to the arousal and sustainance of modern capitalism. Recall the passage that we emphasized in class, where Weber states that change occurred, historically, as "a young man from one of the putter-out families from the town moved to the country, carefully selected the weavers he needed, tightened up control over them and made them more dependent, thus turning peasants into workers (...)" (PE, pp. 21-22).

In class we called this "the invention of enterpreneurship", but don't you think it resembles exactly what Marx would describe as the emergence of the burgeoisie as the dominant class over the proletariat, through the invention of compelling (for Weber, due to rationalization) and exploitative wage labour?