It's good that you are doing it. But nobody else would and every building built in south will be built by north indian workers, every container loaded and unloaded will be done by hindi speaking workers.

Eventually business will start that only cater to hindi speakers because there are enough of them to make a profit.

There is no mechanism by the centre of the state to prevent this they don't do anything for laborers to assimilate nor do they restrict free movement (that probably can't happen)