>Right, this is fundamentally wrong. The only thing that matters is your relationship to the means of production: 'middle class' people are proletariat just like 'lower class' people are. It has absolutely nothing to do with your positioning in the table of income.
I do think it's interesting to look at class from the Marxist perspective, but eh, the Marxist terminology I know is sloppy and inexact at the intersections of class; where a whole lot of the action happens.
Petite bourgeoisie refers both to me, the owner-operator of capital goods who must add his labour in order for those capital goods to produce value, as well as to those who own nothing but manage everything; managers of large companies who might not own any stock at all except for the options given as payment, people employed by the capitalist class to do the actual work of managing capital (and yes, it is complex and difficult (difficult in the sense of difficult to get right, not difficult in the sense of physical difficulty) work.)
I can not imagine two classes of people who are more different. I mean, your owner-operators? The means of production we own? we know intimately and control absolutely. Sure, we might take on apprentices from time to time, and we might delegate some of the less critical work, but room for delegation is limited, mostly because any mistake or misfortune that decreases the value of the capital good we operate generally harms us directly. I still assemble all my servers, because nobody else cares about 1 in 10 or 1 in 100 errors introduced by improper ESD control. But me? I care because I'm the one who has to get up at 4am and deal with the problem. I'm the one who has to make apologies to the customers, and I'm the one who gets to watch my customer base shrink when those sorts of problems happen. So yeah; I'm sure I could pay some kid ten bucks an hour to assemble servers... but generally speaking? I don't. I have people I trust with root that I won't let touch hardware. It's better, sometimes, to do some things yourself.
Your managers? Generally, they have much broader and shallower knowledge. They are all about delegation; not only delegating the decisions, and the work, but also delegating the risk. If a manager screws up, the worst thing that might happen is that they lose their job and any future compensation, usually not even that.
Managers? Managers control the largest corporations around. Owner-operators, usually, control very small operations.
Moreover, the Manager's customers are the owners. Really, the Manager only needs to be perceived as compitent by the capitalists that own the company; the perceptions of the employees and customers don't matter except in how they change the perceptions of the capitalist-class owners of the company.
Personally, I would argue that this manager class; those hired by the owners to manage what the owners have no time, ability, or interest in managing, are now a more powerful class than the actual owners. Mutual funds and index funds are very popular. How many here actually vote the stock they own? Not many, I'd wager. The Managers control most corporations, really, to a greater extent than the owners do. I mean, yeah, every now and again, one of the capitalists tries to fight the managers; even when the capitalist is clearly right he often loses to the manager.