Any large company will have some problems. They attract people who want to say they work there to other people. Name recognition pulls in the posers.
Smaller companies are much better, they don't have time for posers, everyone has to contribute. No time for dirty tricks and dishonesty. Real work has to get done.
If you are looking for a place to do real development, always pick a small company over a larger one.
That said, Oracle is the worst large company I have worked for. In my mind, there is nothing worse than working at Oracle. I think that the acquisition process breeds posers. Those are the people who stay long term. The political struggles that go on after acquisitions, to take power from the newcomers, are what breeds the dirty tricks and dishonesty. People coming into that from other companies catch on quick about what they need to do to survive, either that, or they get disgusted with the whole thing and leave.