Mumbai is what it is today, also because of the non-maharashtrians living there. If outsiders were not permited to work and live, mumbai will never find enough people to work, which will ultimately lead to less industries in the state.
What happens if all non-maharashtrians quit mumbai? The metro rail will run in a loss. At least 50% maharashtrians will loose their jobs. Major industries will be shifted to nearby states since they need skilled manpower in required number. International flights will stop flying to mumbai. Mumbai port can be converted to a huge boating club.
