Actually being a nurse, I'll throw in my $0.02. As a nursing student, I think much of the complaining comes from the ridiculous curriculum we often follow. I remember spending 6+ hours working on charting paperwork that had nothing at all to do with the patient and moreso something for the program to check off that they taught us. The amount of busy work that helps neither the student or patient is insurmountable. Having gone back and also getting a degree in biology, I experienced not even half the bs I did while in nursing school. I also think some people are surprised with how difficult it can be to do well in nursing. I would study ~2-3 hours/day and make As/Bs but studying 10 hours a day still couldn't earn me straight As in nursing. The material itself is pseudoscience half the time. Absolute insanity.
As a practicing nurse out of school, we routinely get s**t on by patients, their families, doctors, administration staff, CNAs, etc. It always seem to fall back on the nurse. This is definitely something I complain about from time to time but I agree with another poster ^^, some people just like to complain and others just make s**t happen.