A few years ago, the state of Maryland needed some more money but the legislature did not want to appear to be raising taxes, so they imposed a series of fees, including additional fees on sewage services, increased fees for car registrations and emissions testing, etc. Calling them fees allowed the legislature to say with a straight face that they didn't raise taxes. Apparently the legislature had forgotten that the taxes the Framers protested included "fees" for things like official stamps and the like.
Callling it a fee didn't mask that it was a tax increase.
Well, another state arm, state univerisities (and private ones too) are so afraid of appearing to have too high a tuition increase they have taken to adding a series of additional fees to student bills.