"Mr. May said that the determination process had become increasingly difficult, however, noting that the Mall of America, a major tourist attraction, was seeking tax exemptions as part of its plans to expand, arguing that it aids the state economy by drawing visitors.
“From our perspective in the assessment field, it’s harder to define what’s a nonprofit these days because there are so many different types, and many of them are doing the same thing for-profit groups that aren’t exempt are doing,” he said...
“The nonprofit sector is being pressed to be more business-like and to find new ways to fill the gaps between what government will pay and what services cost, but then assessors want to treat us like businesses, which pay taxes,” said Jan Malcolm, chief executive of the Courage Center in Minneapolis and a former state health commissioner.”
I can see the merits of both sides of the argument - there have been rumblings in the Massachusetts State House about taxing least ten Massachusetts universities with endowments over one billion dollars. And many tax-exempt churches have been acting nakedly partisan - i.e. stumping for political candidates and other not-for-profit no-no's. It'll be interesting to see what develops, though this is a state-by-state issue, so grad sweeping reforms are only likely to occur on the local level.