Why are some nurses so mean and egotistical to their own staff?

I got into nursing because I loved the whole idea of it...taking care of the sick and helpless, the compion and care...since I have been a nurse aid I have seen a lot and believe me it's not pretty. Arrogance, rudeness, snipey attitudes and backstabbing are at the top of the list of my description of R.N.'s. Most - not all- think they are Gods and everyone else is beneath them. I'm sorry if i offended any good nurses out there,,,but if you think about it you would have to agree with me because you have seen it over and over again.