When I was new to nursing, I heard the saying, "Nurses eat their young." Boy, it is the truth! Plus, they snipe and swipe at each other a lot.
It could be that we are problem-oriented people. We are constantly assessing a situation, trying to find the fly in the ointment, that we can do something about. In that vein (no pun), it may be that we over scrutinize the people around us, and the way they do things.
The other possibility that I see is that nurses are so stifled in just about everything
that they take their frustrations out on one another. Administration doesn't want to hear about problems, or help find solutions, staffing is skeletal, pay needs to be improved, families complain, patients complain, doctors complain, ancillary departments complain, and nurses are supposed to take it all, smile sweetly, and NOT tell anybody to take a flying leap! Factor in kid or spouse or financial or other problems, and you have a powder keg with a short fuse fixing to blow!
If we can just give ourselves a bit of distance to pull back and look and listen to what we say, and how we say it, we might moderate the things we say. After all, the Golden Rule says, "Do unto others as you would have them do unto you."
It does NOT say "do it to them before they can do it to you."
We need to value each other as human beings that are sharing the same place in the Universe. That doesn't mean that you have to like everyone; just be respectful of them.