I think at least in American companies, it's hard to tell whether your co-workers are actually happy, or if they are putting on the expected corporate ExcitedToBeHere persona. You ask 200 co-workers "How's it going?" and you're going to get 200 variations of: "You know, really busy, but it is super-exciting to be meeting KPIs and synergizing the latest roadmap with our external stakeholders, blah, blah, blah." Ain't nobody saying "Well, you know, Bob, things are pretty shitty for me because I spent the last quarter working my butt off and Lumburgh gave the promotion to that idiot he's been banging in the conference room every evening."

Being honest opens you up to having that honesty used against you, so people just put on a cheerful saccharine smile and lie.