I started as a philosophy major and switched to history and economics for this exact reason. My philosophy classes became incredibly disconnected from reality and ended up being endless arguments about frameworks and formalisms, but without the rigor of mathematics outside of formal logic. I still loved my philosophy classes, but I'd recommend anyone studying it as their first undergraduate degree pair it with something more concrete.
I don't agree. There is a good line in the book "Impro" about good and bad teachers. It says that we think of "good teachers" as providing a lot of some substance called "education" while "bad teachers" provide only a little. In fact bad teachers can and often do not only fail to provide education but actively make students less educated by, for instance, teaching wrong ideas, punishing arbitrarily, etc etc. The same is true of managers. They can easily drop below zero and start to have a negative impact on productivity and their employees.
I'm a history/philosophy major who ended up as a programmer. Pure speculation but I wonder if another part is that history helps you think hard about groups of people and how to lead them / how they work together. I think it also conveys things that traditional management theory might not (I haven't studied it so I can't say for sure), but things like uncertainty and the contingency of events come through in a big way.
My advice for any younger people reading this is to do something practical and something for passion. I regret not getting a technical education that would have had much better employment prospects and having to claw my way through the back door, but I also wouldn't trade away my humanities education for anything.
EDIT: FWIW I did not go to an elite university and make a good living as an engineering manager. I also talked on a plane once to a guy who said the best people he met in IT were NSA cryptographers, but the second best were people like me. His theory was that people who studied humanities and then went on to do technical work must have had a passion for it since they had to work extra hard to get into the field. Maybe that's a big part of it, maybe studying history has nothing to do with it and they just went into other high paying fields.