In my own personal experience of that shit, it's just plain managerial incompetence at all levels - basically "bums on seats" is an easy thing to measure whilst in Services, outside domains with actual direct easy to measure results like sales, actual productivity is hard to define and hard to measure, especially in areas like Software Development where most projects are unique, so whenever you have management styles which are low on analysis and organisation - typically places with shot-from-the-hip management - you see low and mid-level management quality being judged on such easy to observe and measure things like people working more hours ("he inspires his people to work hard") rather than on things which are much harder to measure in a way which is standard across projects which are highly correlated to productivity.
From what I've seen there's a huge cultural component to this: countries with cultures which value being organised a lot have much more structured ways of work and of measuring the output of work and those are also countries where working long hours is rare, were countries which value improvisational skills above organisational (like my own Portugal, which in addition to one for "improvise" even has a unique verb for solving something on the spot without preparation) tend to not have standardized ways of measuring the output of work (unless that output is something obvious, like manufactured widgets) and working long hours is very common.
I don't think this is at all 5D chess by the Oppressor Class in Capitalism, I think it's a reflection of how much the local culture values organising and preparation as skills.
Now, people working long hours because they have to have multiple jobs to be able to survive, that's a different story and you would probably be right if you were saying that about those situations.