The sooner students learn to use their strengths and to recognize and work around their weaknesses, the better off they will be. Students are responsible for arranging their lives around their priorities. If a student needs a certain grade in your class to change majors, stay in school, get a job, win a scholarship, inherit a fortune, etc. Students who are painted into corners have done so themselves. At worst, you will be the last straw but you did not put all the straws on the camel's back and you did not choose the camel.
Students are responsible for managing their time.
If a student is working two part-time jobs, taking 18 credit hours, helping out at the soup kitchen and failing your class, he or she is still failing your class. In sacrificing a grade in order to tutor the illiterate, perhaps there is some nobility. There is none, however, in taking on too many activities and then expecting everyone to accommodate you. Both authors had successful careers before returning to school for PhDs. We worked with the competent and the incompetent, the ethical and unethical, the excellent and the overwhelmed.