1. Not for ambitious people -- Because of the constricting environment, many smart and ambitious people leave very soon, or worse become stagnant in their careers.
2. Forget meritocracy, you need to threaten your boss with your resignation to get a raise or promotion -- when I quit after 4 years with 1% salary raise in these 4 years combined (I had an "exceeds expectations" rating throughout) , my manager says "hey, we were planning a salary raise and promotion for you next cycle, so stay back". I have seen people resigning, get a raise/promotion, and withdraw their resignation. I have also seen people receiving the stellar ratings 5 year in a row, with no salary raise or promotion.
3. No employee development opportunities -- if you're based Onsite, they won't even pay for taxi fare (like $40) to visit a test location to take Infosys' own certifications, they won't pay for educational material (books, magazines) forget about sponsoring conferences and workshops -- but they will claim to the clients that they have industry's best consultants.
4. Highly bureaucratic -- processes are created for the "sake of process", not for the benefit of the client or the employees; and if you get stuck in one and recommend an improvement even politely, be prepared to face the wrath of the senior management of that team
5. Bully culture -- Senior managements from other departments will frequently make you work for their teams saying "you don't know who I am and what I can do"
6. Global Immigration team is unbelievably poor -- for a company which has the world's leading number of H1b applicants, they are an unbelievably inefficient bunch, and have processes that make absolutely not sense (they wrongly filed my visa application TWICE !)
7. Super-deceitful environment -- the managers will take you for a spin, they'll promise you gold if you work hard and deliver but you won't even get dirt when you do all the work they ask. I have known people decline offers from tech giants when their manager promised them a promotion/raise/Green Card, only later back out of it (read pt. 1 again). Basically every manager has an "attrition" goal, so they'll promise whatever it takes (even over email) to keep you in their team.
-- because of the above reasons, talented people leave the company. I have found 95% of the people I know in the company to be incompetent and poor at their jobs, especially the mid-management and people managers. If you're reading this and are among the 5%, I'm certain you're thinking to move..good luck :)