I think we often have rules applied to the age of majority. We thought it was just fine the way it had been, so we were changing it back to the way it was. The cut-off age of 18 is often the case, because that's the age at which a person is judged to be an adult.
I don't think it is terribly important one way or the other, because I do believe that if you're a 16-year-old or a 15-year-old, one thing you're going to do is learn English or French, if you don't know it already.