It's probably OK; the devs themselves lose perspective on what they're working on as the deadline approaches: is this really fun? what are we giving up our weekends for? christ, maybe I should be doing financial coding; I hear they make bank. They go home and tell their spouse about their crappy day and how much the game sucks, and the spouse gets even more concerned: not only are they watching their loved one be "abused," but apparently it's for no good reason. (Note: in late '90s and early '00s at EA, it was for no good reason)
In the end it is hard to know up from down. I won a hundred bucks off a guy on the team who predicted our last game would Metacritic at 67%, and I knew we'd at least get mid-seventies. As it turned out, we were an 85% so my perspective was pretty shot as well. The game sold great, and all the crap we thought we'd get killed for was never even mentioned once in any review.