I think OP is full of fail in his mentality, but I will say this:
Before email and cell phones, people were more cautious with their after hours work. For the most part, they really couldn't work anyway, and managers would be less intrepid with their request to have people work on the weekends. Violating family time was a more serious offense.
Now, email, cell phones, text messages, etc. violate every area of our personal time. It's getting worse, and it's to the point where if a person says "Oh, I didn't see that email" you're met with looks of horror. I have clients that email me almost 24 hours a day, send requests on the weekends, etc. I have nowhere to hide. Everywhere I go I feel the burning sensation of someone else's priorities in my schedule.
So, times have changed. OP is living in older times, especially given his line of work. I think there needs to be a balance though, because there is a point where working for free is little to the benefit of yourself, especially if no one takes notice. spidey's point about the boss looking like he's working is a valid one here, because it's likely the case. Anyone fairly savvy in playing the corporate game knows the art of making people take notice of your efforts without making it too obvious.
/longer reply than anticipated; just had my morning espresso