The workforce is older and thus younger employees might less people to mix with on a casual basis. Additionally, Exxon is very traditional company in terms of structure and management style. Very clear organizational chart lines let you know where you stand. Promotions seem to be based less on employee formally expressing an interest or applying to internal positions and more about the senior leadership deciding when you are ready and where you should go -- whether you initiate or desire that move is not a high priority. Finally, those that want to enter upper management will probably have a rotation at a refinery which is not the most desirable place to spend two years.