Well we wont let those same people buy booze or rent a car so we clearly don't think they are responsible enough to make those big decisions.

If we are already deciding what people under the age of 21 can do we should probably add giving someone a unforgivable loan that could put them in debt for life to that list.

Also I'd argue that googling for 30 seconds to determine your future career is just as stupid as taking a check and figuring it out as you go.