Discipline

Some people think that discipline is a dirty word. I understand only to well how we learn certain concepts in life through our own experiences and frames of reference. But if we apply "discipline" to the thing we want or love, all it really means is sticking to a regular schedule with it and making it just as much part of our routine as everything else that we do daily or weekly. Why is it so hard for some people to commit to even 15 min. a day at their instrument, or computer, or medium of art?