I'm not surprised at all. Between friends who work in finance and friends who work in the nonprofit sector, I can tell you that one group never got forced to cancel their birthday or holiday plans at the last minute to cover for some giant screw-up on the boss's part while said boss spends the same evening at home with the kids, and the other had things like that happen almost regularly.
Which isn't to say that finance jobs aren't stressful and grueling, but they at least seem to be a bit more inclined stop short of being personally cruel to their staff.
"You should be happy to work here, we're doing God's work" is a powerful force that's easy to abuse. And, in finance, everyone knows that nobody else is there for the deep personal sense of fulfillment, either.