Rambam on Teacher Accompanying Student to Exile

The Rambam explains that a teacher must accompany a student exiled for accidental murder because “life without Torah is like death”—learning Torah is essential to the student’s life. However, this seems to contradict the Gemara, which applies the halacha even to an unworthy student (תלמיד שאינו הגון). If so, the reason can’t be solely that Torah is essential to his life, since such a student may not be a true learner. This challenges the Rambam’s explanation.