Our contracts are clear: our annual evaluations are based on us meeting all of our contract obligations. The contract obligations cannot be met within our set hours, so in order to keep our jobs, we have to work longer hours.
There's also the problem that, in some states, work slow downs (where we work only our set hours and no more, no less) are treated the same as strikes which means we can all be fired.
I agree that, often, we take on more than we should, but in reality, we don't have much of a choice these days. I'm up late hoping the dang on-line grade book will finally work so I can post grades that are due in the morning, but the stupid thing isn't working. If I don't post on-time, that can be held against me (and my principal is sure to say something), even if it's not my fault that the system is down. That's just the issue right now: add in the mandatory lesson plan forms, the mandatory parent phone calls, the mandatory meetings and training, the mandatory strategies we are all supposed to use in every class and every day even when it doesn't fit, the mandatory this, that, and some other thing (and now the principal is talking about extra meetings/training on Saturdays--unpaid and not mandatory but in all reality required), and you can start to see why we're all so dang tired, and I haven't even started talking about the students.