Managers and executives aren't capital. In fact their relationship with capital tends towards adversarial.

Middle management certainly aren't, that's true, but CEOs often are, or will soon join that group due to their income. It's true that preferential treatment for the C-suite is more a second-order effect, though. A mechanism by which favors are exchanged among and between capitalists, both as a high-tier reward for good servants, and deliberate leverage of the principal agent problem to capture more value personally for those with connections. A CEO can make choices that aren't necessarily the best for their company, but do scratch someone important's back or get them a personal favor of a similar sort elsewhere—see also: board members.

So, both because these positions are sometimes occupied by full-on capitalists (who will accept very few restrictions on their behavior) and because, when that's not the case, they're occupied by people who are being rewarded by capital (often for nepotistic reasons) they have much greater freedom than those lower down the org chart.

I do think this is a general behavior of class systems—and so, probably any large human organization—however, and not particular to capitalism, and certainly there are better-off and worse-off classes in term of norms and treatment by society, short of the capitalist class (as Fussell observes in Class, with his "mid-proles" subject to close monitoring, tight restrictions on time, drug testing, and other humiliations, while his upper-middle drinks on the job, has their own office with no-one watching what they do, would be outraged at having to submit to piss tests, and cuts out early for golf without consequence).

In this case the name just happens to tell us, very directly, who's on top of the pyramid. Not like other systems that may try to obscure who's the most-favored group.