A lot of the time when I see people produce really crap code it's because they just don't care. They show up for work and anything that meets the minimal standards is fine with them. There's no passion or interest in doing more than absolutely needed. This isn't about "hours worked", but about passion and trying to make whatever you're working on the best it can be. You can do that perfectly fine in just 40 hours/week.
But yeah, some people seem to conflate "passion" with "work your ass off for 60+ hours/week", and that's just silly.