They have single client where almost all employees are deployed. Less job security.
Lot's of politics onshore folks do. They treat themselves as manager, they don't have ethics that how to talk. Very poor English communication, if you work for 10 year you will be developer only. There are lack of quality work. Some time you may end up writing test cases for more than 6 months.
People are getting frustrated and suffering because of lack of management and dirty politics.