Amateurs see feedback and coaching as someone criticizing them as a person. Professionals know they have weak spots and seek out thoughtful criticism.
An amateur is a person who does something for enjoyment, not money, like an amateur who paints as a hobby but earns a living another way.
Amateur sports are sports in which participants engage largely or entirely without remuneration. On occasion, cash prizes, particularly in individual competitions, could make up the difference; some competitors also wagered on the outcomes.