If the department I manage was required to train their replacement because the company could save money, we'd all walk off the job. I'd lead the way.
I believe that would cost you a severance package -- something that many couldn't afford to do especially considering they would be unemployed.
Along with importing foreign tech, this country needs to wake the hell up and reform the education system. Reforming the visa bill will be meaningless without it.
That is true with many of the reforms that are proposed.