Reason for being non-free: various & unclear. internet-developed software from the dawn ages before we realised explicit licenses were needed.
Russ Allbery: "This is partly replaced by mailpost and/or news2mail (I forget which direction newsgate goes), included in INN under a better license. A bit of additional development effort would likely kill newsgate completely; it's not a very complicated program, particularly when written in a better programing language for string manipulation than C."