To be fair this happens because there are those who are willing to hurt themselves in order to get ahead in their career. We've all had coworkers that send late emails at 2am in the morning or don't use up their vacation days because they want to appear as hard working and as loyal to the company. Many of these people have no real skill and sacrificing their free time is the only real edge they have. This is fairly common and observable at your standard big enterprise software corp. Not trying to shift the blame from companies but it does take two to tango.