That would be an investment worth making in order to ensure the long term prosperity of the United States. To make it free for everyone could possibly turn it into a less professional atmosphere (strong emphasis on the word "could", whether or not we should completely socialize university costs is another debate for another time).
The way student loans are made needs to be reformed.
As someone with student loans, I can certainly say that they limit my own economic participation. Many people finish college with loans of twenty thousand or more, and spend a lot of time paying that back. Monthly payments, even with low interest rates, can be high and make it harder for college graduates with loans to get a car, or to buy a house.
Student debt is at an all-time high, and is only continuing to grow with the absurd price of higher education. Meanwhile, our economy has plummeted and many people are having a hard time finding jobs, meaning its getting harder and harder to pay off that debt. The debt is preventing many people from spending money on non-necessities, which is a huge hit for the auto industry, housing market and many businesses across the nation.
There are more students in law school than there are lawyers/law firms. The same goes for many other professions. Besides the fact that there aren't enough jobs to help pay the debt, the schools are charging too much. It doesn't look good when schools are in it for the money and not for the education. My cousin went to F.I.T, it's like the Harvard of fashion school. It was mandatory for her to take, and ultimately pay for a class about bowling or Frisbee (she had to take either or). That's ridiculous. Why does that have to do with fashion? Schools are corrupt and aren't focusing on what needs to be taught. It's all about the money for them, and no one else.
People that have student loan debt may put off things such as buying a car, a home, investing, or opening a business because their extra money is going towards their student loan. All the money that they are putting towards their student loan might otherwise be spent or invested strengthening our economy.