It is difficult to define "art," but it is easy to define "fine art."

"Fine art" is art for display only, not for illustration, document, journalistic purposes, commercial applications, advertisement, etc. "Fine art" does not mean "art" or "good art" or "great art."

"Fine art" is opposed to "applied art." Specific works of "fine art" may be crap, and specific works of "applied art" or "illustration" may be great art, but there is nothing in the terms "fine art" or "applied art" that suggests one or the other.

"Fine artist" is something you can put on your tax forms. "Artist" is something that it is up to future generations to decide.