Capitalism and unfree labour Book

This is a groundbreaking work of the analytical school within Marxist tradition. It deals with some interesting topics, but I found it marred by certain conceptual flaws that somehow framed the argument the author was trying to make. Of course if one acceptes the premises he makes, the argument flows nicely, but I think some of them are either controversial or false, which kind of undermines the whole relevance of the arguments made.
For example, in Chapter 1, Przeworski says that capitalism is "a form of social organization of production and trade, based on an advanced division of labor, oriented towards the needs of others, towards commerce" (I'm paraphrasing as I read a translated version). I think this is not really accurate. Satisfying other people's needs might be the ultimate objective people expect capitalism to fulfill, but that is not the orientation it has. Capitalism is purely orientated towards the production of benefits, end of story. The idea would be that by having the incentive of producing benefits, both the division of labor and production would be oriented towards satisfying the needs of people, but capitalism is perfectly able of generating benefits without satisfying needs. A fine example would be the recent case of Martin Shkreli, who manufactured licenses on several life-saving medicines and increased their price by more than a 5,000%. Clearly, needs here are irrelevant for his company: his sole motivation was to increase benefits, regardless of who's left in the curb.
Another conceptual problem is at the basis of Przeworski's discussion of the trade-off between parties recruiting working-class or middle-class voters. Przeworski talks that before there is a class struggle between classes, there is a struggle to define classes themselves. A struggle over class before there is a strugle between classes. Yet at the same time he does mention some "objective" notions of what the working class is. This somehow echoes the debates about what a social class is and its potential mobilization in political struggles (the most extreme of them being the Laclau idea of everything being constituted by discourse, with no materialistic grounding, something attacked by amongst others, Norman Geras). Yet it is even more confusing because it sometimes seems like Przeworski wants to keep both ideas at the same time without explaining the extension to which each one applies. in the end, I didn't really know why he chose to define the working-class as narrowly as he did, what he understood by the vague notion of "middle class", and what criteria he thought were the ones that could clearly differentiate "class identities" (and why they couldn't be "blurred" in political action). I think Erik Olin Wright's work on what are social classes, how they can be differentiated and how they form their identities on the basis of the dynamics of exploitation to be much more useful and elegant (incidentally, during Wright´s courseshe has dealt with this exact issue inthe dialogues with his students).