Music students should know how important ear training is for their development. Also experienced professionals still need to stay in shape, especially with the rhythm. Even those not interested in music should realize that a "tone-deaf" ear will somehow affect their personality as a whole. The very first requirement for a musician is to be able to imitate sounds. You hear sounds in your imagination or from the outside world. You should be able to replay those sounds using your voice or an instrument.
Technically this is what making music means. Musicianship starts here. A professional musician, especially one with the perfect pitch may consider this as childish. In fact even a pro should strive to improve the ability to memorize and replay sophisticated rhythm patterns. This contributes a lot to better musical phrasing.
It doesn't make sense for someone to learn how to read music or play a musical instrument, and not be able to imitate sounds with the voice or the instrument.
Of course, music comes from the soul, it is not a mere juggling with sounds, but too many times players from a lower spirituality platform look better just because they have "a good ear", and a common misconception is that this cannot be improved.
I can assure you that the attentive ear can be improved to the highest levels, even for someone considered tone-deaf. It requires a lot of practice and discipline.