Work/life balance, absolutely. I've got a wife and kids. I don't live and die with the project meeting some arbitrary deadline. You want it to ship by a certain date? Fine. Control the feature list. You want it to ship by then plus have all the features everyone can dream up? Sorry, I'm not going to kill myself to make it happen.

Now, in this business, I get that crunch time happens sometimes. I accept it as part of the job, as long as it's rare. One month a year is reasonably rare. (On my current job, it was one night in seven years.) One month out of two is not rare, and I won't put up with it.