While I agree that it is difficult for an athlete to maintain a job, you may wish to review #s 9 & 10:
9. Outside employment. The NCAA allows players to have paying jobs. They may rarely have the time to do so, but it is permitted if the work is performed at an amount comparable to the going rate in that area for similar services. The payment isn't supposed to be due to athletic ability or publicity for the employer due to the athlete's presence. An athlete can be employed by his or university, another school, or a private organization to work in a camp or clinic as a counselor.
10. Self-employment. This NCAA rule still says an athlete may establish a business only if his or her name, photo, appearance or athletic reputation are not used to promote the business. But the NCAA now tackles this issue on a case-by-case basis and has said it will grant appropriate waivers if athletes have similar opportunities as other students for entrepreneurial aspirations. Most famously, Minnesota wrestler Joel Bauman tested the NCAA in 2013 by promoting that he was an NCAA wrestler on a music video he produced. Bauman declined to remove his name from any songs and eliminate any promotion of his status as an NCAA athlete. He got declared ineligible, a firestorm erupted, and he brilliantly turned the publicity into a marketing job.
As an aside, your prior comment that a band member may write a song and sell it on iTunes is an opportunity for open to athletes.