Hiding their money

The Paradise Papers focus on secretive offshore investments. Surprisingly to me, colleges - especially the upper crust - engage in this activity. I can understand why companies or individuals use these secret, low tax investments, as their job is to maximize profits within certain humanitarian limits. I find it hard to see why such activity can be considered morally correct for colleges. It is true that when schools earn income from enterprises unrelated to their core educational missions, they can be required to pay a tax that was intended to prevent nonprofits from competing unfairly with for-profit businesses. But, isn't their first obligation to their students? Could they not use that money to lower tuition? Which would result in lowering the massive debt many of these students assume.