Memes

Management is labor, sure. It all adds to the collective labor expended necessary for producing a widget, say, 1 hour of cumulative labor expended through dead labor (the percentage of tools used up) and living labor. Let's put constant capital at .5 hours, and variable at .5 hours. The value of the widget is 1 hour of socially necessary labor time, and it is sold for this price on the commodity market when supply meets demand.

Where do profits come from, then? From living labor. The price of the commodity labor-power is regulated around the average cost of subsistence. A worker may only need to truly work for 3 hours in a day to produce their social consumption, but they are paid for those 3 hours as spread out over 8, 9, 10, etc. hours. The difference between paid hours and the unpaid hours forms the surplus value extracted, which is the chief component in profit (though not the same).

That's an oversimplification, but the point is that ownership adds no value. Management and administration can, but not ownership alone. It is only ownership of the constant capital that the owner entitles themselves to the profits, participating in a Money -> Commodities(means of production + labor power) -> Production(combination of MoP and Lp) -> Commodities' (greater value than original commodities) -> Money' (greater sum of money than originally fronted, fresh for the surplus to contribute to subsistence of the capitalist as well as expanded production). This is just a Money -> Greater Money circuit, which exponentially grows, the only action being buying and selling from the owners perspective (and this is often automated by having others do it).