Two pieces of advice that shouldn't have to be said - Never miss job interviews without cancelling and never quit without notice unless it's some kind of contract job where that's considered acceptable practice. While I have problems with the idea of blacklisting, this is the real world. Professional communities talk.
Also, I don't care if you work in an esoteric white collar job or you do manual labor for a living - Working hard will never hurt your chances at career success. And with the economy getting the way it is, and companies looking for ways to cut back costs (and labor is a huge cost), you aren't going to survive unless you're some kind of distinctly value added proposition to the company. If you really don't think this... I hope you have a really cushy position setup for yourself.
Like a couple people here have said, no personal pride in not working hard. You can tell yourself you're being rebellious and trying to have a work/life balance all you want... You know you're being lazy and you will feel worse about yourself.
All that said................
I don't know if the American workplace changed or if the American public did, but it's harder to ignore how much work sucks these days. It's nearly at the point where you watch something like Office Space, which was deliberately designed to be satire, and you think "this would be a relatively sane office environment."
It gets harder and harder to find people who know how to do anything. People whose job it is to make things over-complicated are constantly trying to make it even harder. No one can make a decision because no one wants to be responsible for anything. And now wanting to take responsibility for yourself and your job is seen as some kind of weird stepping outside of your boundaries. Maybe trying to juggle multiple requests from multiple people that you don't actually have time for isn't some kind of normal part of work and is in fact a sign of deep organizational dysfunction. You're told to come up with ways for the company to save money and then have to make laboriously researched reports to demonstrate what should be intuitively obvious, so no deeper questions are ever actually asked because there's no time for them. All the executives are bull-headed and none of them really understand how the business operates, so massive amounts of time are spent putting things into PowerPoints that they can understand. Oh, two VPs are having a disagreement, time to marshal their teams together to make competing sets of spreadsheets so they have ammo to argue out their points.
Okay I'll stop now but I think you get the point.