Ok here is a theory about why nurses are so negative to each other especially their young.
It is a viscious cycle. It started with the nuns who used to teach nursing. Anyone who has had experience with a parochial school (raising hand) can testify that nuns can be really brutal. Not ALL but enough. Anyway, way back when they traumatized the new nurses so badly that when it came time for them to help train in the new nurses they essentially were like either "this is how you do it for the nurses own good" or "this is payback time" ie now I can ruin someone else like I was ruined ie take away all their starry eyed idealogical ideas/attitude.
I think it was so effective because it is often done under the guise of making someone feel like if they don't put up with the harsh discipline they are going to end up "killing" someone. Nurses are SO catty about even a slight med error. Some act like OH MY GOD you almost killed someone even if you didn't.
All nurses biggest fear is that they will hurt someone on the job. Thus a huge undertow to the vicious cycle is the fear all new nurses have about making a serious mistake. When they inevitably do make a mistake because they are human they are treated horribly and made to feel like you are a "DANGEROUS" nurse. Even though the "punishers" themselves have made maybe worse mistakes.
There is a huge shaming subculture in nursing and the only reason it perpetuates I think is because it is all under the guise of "protecting patients". But patients are not protected because downtrodden nurses are MORE likely to make mistakes.
Nurse are human and they WILL err. It is time to quit shaming them for being human.