The reason that they are being cut off GIS is that they are getting a larger CPP.  Therefore they are still getting the same income in retirement, but it is coming from putting away money during their working career, via employee CPP contributions, their employer's CPP contributions, and investment income earned by CPPIB.  Isn't that a good thing?  

The only thing that you can argue against is that Canadians are forced to save through higher CPP contributions so take home pay will go down slightly, but having people save for their own retirement is, IMHO, a good thing!