Try thinking about it this way:
"Homes have become too expensive and should instead be heavily subsidized because it is fundamental to our economy and to the success of individuals--even longevity. Free homes should be next. You think this harms those who paid their mortgage. I paid my mortgage and I don't object to this program in any way. It helps everyone by aiding the economy. Frankly, the level of debt only served the interests of banks and credit card companies. Try raising a family when a mortgage takes up much of your salary."
If you're honest with yourself, you would have a problem with that. What is the difference for you that makes this ok for college loans but not for mortgages?